None. I wouldn't extend any young player as long as the arbitration system exists (look how well it's working out for ATL and previously the Hahn Sox) unless they're Juan Soto. We'll see how it goes for Basallo, Anthony, Chourio, whoever else. Doesn't seem worth the risk. I wouldn't extend Colson at this point. I'm not sure extensions was the discussion anyway, but rather free agency.
I'm simply replying to the percentage of payroll point. I think one just looks at the flat amount in this case. $3.5mil is practically nothing for a free agent. It's obviously an overpay for Rojas, it's double what Tauchman is making, but it's not like it hamstrings the team in the same way a Benintendi-esque contract does. SFG is clearly keen on spending money and look how it's working for them. Adames is not a bad player, but the Sox would be totally screwed if they signed him to that contract when you can pay Meidroth, Montgomery, Billy Carlson combined 1.2% of the price. Nobody is going to be thinking about Rojas next year. Maldonado signed for more money than Rojas did and it's dubious to think that affected JR's intention to spend money. Sure didn't stop 'em spending on Rojas...who was probably worth the risk if he could've produced 2-3 WAR (as he has in the past) at that price. The Pirates, a notoriously cheap team, paid considerably more (roughly x1.5) than we did on Rojas for Tommy Pham, and they didn't trade him despite being better, or roughly the same, this season as he was with the Sox. Is that gonna change the Nutting logic?
No money was being spent regardless and they'll probably spend next year on a bunch of $2-5mil guys who may or may not produce. Slater returned something, Fedde returned a lot more than he's actually worth (which MLB teams clearly noticed). All in all, the Getz position player free agents have not generated any trade interest while the pitchers have, but signing them also did not cripple the team in any meaningful way. I think we're getting past the point of trying to sign guys to trade for prospects and we should start building a winning team. At the same time, what other teams are signing position players for that amount and then trading them for great players/prospects after half a season? I'm trying to find some examples and not seeing any.
I'm thinking about Tommy Edman vs Miguel Vargas. one guy is 30-years-old, OPSing .677 and is being paid $74mil dollars; the other guy is 25, making $770k (more if you extend it out 5 years as with Edman, obviously...maybe it's more like $17mil vs $770k) and is OPSing .704. Both are exactly the same bWAR and one guy is getting old and the other is just starting his career. Erick Fedde doesn't even look like he belongs in the MLB once again, he has an even worse ERA (7.11) than he did with the team who DFA'd him. Sox also got some prospects in return. It's clear who won that trade.
To your other point, it's a good point but we'll see. More revenue is generated if the team is actually good in the case of the Sox. If there's a free agent who fits a need on a winning team, they might sign him, and it likely produces more revenue than whatever the expenditure is. It totally depends on the talent evaluation. They signed Benintendi, didn't they, when a cheaper option like Teoscar Hernandez or Cody Bellinger was available and both are simply better at baseball. It was an issue of player evaluation, not money. Not expecting them to spend this coming free agency, I'm also not sure who they would spend it on...outside of Tucker who fills a need but could very well turn into Benny. As I said in a different post, Getz will actually be put to the test in 2027 and I dunno how to speculate on that.