I think one contract that makes for an interesting touchstone for Giddey is Dejounte Murray.
Murray started his career as an excellent defender who wasn't getting much offensive burn as he was lower in the pecking order and couldn't shoot at all. But in the last few years he was given much more responsibility on offense and his defense pretty much fell off a cliff (Since leaving SAS he has been a negative defender, but not a catastrophe).
Murray had 1 year where he was given number 1 option status for a full year. He put up 21/9/8 and made the all star team on a Spurs team that didn't make the playoffs back in 2021/22. He was traded to Atlanta that off season. When that trade happened he was on a good contract (2/35 remaining), but the Spurs wanted to rebuild and were concerned about probably having to max him if he stayed there as the first option putting up those sorts of stats.
The return the Spurs got was Danillo Gallonari (expiring filler salary), Charlotte 2023 1st (lottery protected, didn't convey, turned in to 2026 and 2027 Charlotte 2nds which look like good value seconds), Atlanta unprotected 2025 1st (Just turned in to Carter Bryant at #14), a 2026 Hawks/Spurs swap unprotected, Atlanta unprotected 2027 1st.
Clearly the Spurs sold at the peak and managed to get maximum return. Even at the time it felt like an overpay for him, but I have been a bit of a Murray skeptic (ironic I know).
In his first year with Atlanta, Murray put up 20/6/5 as the second option to Trae Young (18 shots per game though, just less ball handling and being the number 1 whenever Trae was on the bench/injured). The Hawks underachieved as the Murray move was supposed to be their all in contender push but they finished 41-41 and lost in the first round (the same as the year before, and worse than their conference finals run 2 years before). It became clear that his defense wasn't as advertised and his fit with Trae wasn't very good.
Murray was now an expiring 1/18 and the mood on him had soured, but he was still viewed as a solid starting level player. He got a contract extension of 4/120 which was well received by most.
https://www.reddit.com/r/nba/comments/14rqc81/fischer_there_continues_to_be_optimism_among/.
I know that is only a reddit source, but I remember tv shows, realgm, podcasts and youtubers all having similar majority sentiments to the comments in that thread.
In his second year with Atlanta, the Hawks went 36-46 while Murray contributed 22.5/6.4/5.3. This was boosted by Trae picking up an injury and missing essentially the entire post all star break (A time period that parallels what we saw with Giddey post Lavine) and during this time Murray put up 24/9/6 on very high usage (30% usage and 21 fga). By contrast Giddey's stretch was 21/9/11 (25% usage and 14.5 fga post all star).
After this 2 years was up, with Murray about to start his 4/120 extension (final year player option), he was traded to the Pelicans.
Atlanta's return was Dyson Daniels (A calculated swing on an underachieving prospect that paid off), Larry Nance Jr (probably worth seconds) and some other expiring filler, as well as the 2025 Lakers 1st, and the less favorable of the Pels/Bucks 2027 1sts with top 4 protections. The Lakers pick was traded to dump Terrence Mann's 3/45 contract and bring in Porzingis. Obviously Daniels has also had a major break out. What this shows is that even on a long term 30m AAV contract, and with him being viewed less favorably over time, Murray was still able to generate significant positive value in a trade.
The Pelicans are viewed to have lost this trade, but a big part of that was Daniels breaking out and then what happened with Murray and the Pels. This season the Pelicans were an injury riddled basket case of a franchise. Murray himself had a broken wrist, came back and played 30 games at less than his best (17/6/7 with bad efficiency) then did his Achilles. Now his contract is underwater because he is going to be out for all of next season, and on top of that the Pels have pivoted to a youth movement. Murray actually makes sense as a veteran for them going forward if he is still good post Achilles. But right now the contract is definitely negative as the worst case scenario has occurred.
Clearly all of what I have written on Murray is very mixed. But that is a big part of why he and Giddey make for good comparison. They both have similar flaws and similar strengths which means Murray can be viewed as a bit of a canary in the coal mine for the Bulls with Giddey.
Dejounte Murray is one of the most comparable box score players in the league to Giddey when played in a similar role. Giddey is a better rebounder and passer, but Murray doesn't turn the ball over as much. Murray has consistently been a poor efficiency guy (best ever True Shooting is 55.5%, career 52.7%) and Giddey has also largely been inefficient in his career so far (Best TS% 57%, career 53.5%, improved every year so far). Murray has been a shoddy 3 point shooter during his career (34% for career), but has increased his volume over time. Giddey is at 33% for his career but has improved each year and increased his volume this past season. Murray is not a guy who generates many free throws, and Giddey hasn't been so far either, but showed some good promise last season. Murray led a mediocre Spurs team to the play-in as the number 1 option as a 25 year old, but never got that role again. Giddey has done similar with the Bulls this year with a similar level supporting cast but at 22 years old. Murray during his prime has had some troubles fitting in as a secondary option because of his shooting and defensive woes which mirror Giddey's career so far, except Murray has still been afforded a high volume of shots since giving up lead ball handling duties.
So what is different between the two? First, Giddey is several years younger than Dejounte when he went to the Hawks, and when he signed his extension. Second, the Bulls don't have a Trae Young type player that will inherently depress Giddey's value and production like he did to Murray. Third, the Bulls don't have a 'superstar' like Trae that they are constantly trying to appease and make happy. Fourth, Giddey has not picked up a devastating injury which is what made Murrays contract a negative (it was traded at significant positive value before he got injured).
Something that is similar is that both teams gave up something significant the year before negotiations. Caruso for the Bulls and I mentioned the investment from the Hawks earlier.
I think the level of player Murray has been represents a realistic middling outcome for Giddey. We have seen what that player got paid, and how his value has evolved over time in different circumstances. It took a huge injury, plus multiple teams losing trades when acquiring him, plus his teams underachieving each year, plus him now not having 'upside' for him to become a negative asset at 30m AAV.