TEs are literally the opposite of RBs, they're hard to scout and take forever to develop. You're taking the Tonyan contract and expecting it to be normal for the market - it's not at all. Tonyan's contract is an aberration:
-The TE market is depressed this year due to the strong draft class
-Tonyan is a local guy, who knows the system and wasn't wanted back on his old team because they're broke and won't have AR12 going forward
Kmet is going to get a decent deal here because:
-He's young (just turned 24)
-He's an above average starter
-TE is absurdly hard to project from college to the NFL (the last good TE draft was 2017, only Kittle turned out to be a player absolutely better than Kmet from that class
2017 NFL Draft Listing | Pro-Football-Reference.com)
-TEs take forever to develop and the Bears want to be good in the next two years
-TEs have gotten PAID on the open market recently - (Austin Hooper 4/$42M, Njoku 4/$52M, Hunter Henry 3/$37.5M, Jonnu Smith 4/$50M) and those dudes all really didn't pan out.
They could draft a TE and it would take us probably 3 seasons before we knew he was better than Kmet. They can't run that risk considering what they're trying to do in the next 3 years.