Interesting, I hadn’t even thought of ordering the whole thing new, figuring it would be cost-prohibitive. Installing myself is always preferred.
One site I pulled up which shows the whole exhaust system is
this one which shows $3000 for the Y-pipe+Cat 1+Cat 2.
The part numbers from this diagram:
View attachment 4081263#1 Manifold 1: 17141-66020
#2 Manifold 2: 17142-66010
#3 Gasket 1: 17173-66020
#4 Gasket 2: 17198-66010
#7 Y Pipe + Cat 1: 17401-66090
#8 Cat 2: 18450-66120
#9 Muffler: 17403-66041
#10 Tail Pipe + Resonator: 17405-66010
The big dollar ones are #7 and #8. Lowest I'm seeing these for is ~$1750 and ~$750 respectively before taxes/fees/shipping. Granted, these are brand new Toyota parts, so not directly comparable to what the shop is offering, but the price range is not insanely off as far as I can tell. I am new to exhaust however so I'm open to any and all suggestions!