re: A/C Evaporator Coil Replacement

That's a fair price, especially today with inflation and whatnot. I got a Rheem 3 ton furnace and coil for $4000 cash back in 2021 but my contact also does the HVAC work on the side and not full time so I think I got a good deal. So $5000-$5500ish sounds reasonable. You also didn't mention tonnage.

Also, be sure they use the proper type-B ducting for the vent on the furnace if it's gas. I think most HVAC companies would know this but you never know.

EDIT: Good thing you're doing this now before the 2025 refrigerant change. That would make it considerably more expensive and would require a new compressor unit as well.