I'm looking for something in the 3-3.5 ton range (what I have now is 80,000 BTU 3 ton, 12 year old arcoaire furnace and A/C unit for 2 floors and a basement).

Just spent some time looking at models from Trane, Carrier and Lennox.

My head is swimming with things like AFUE, SEER, variable stage blowers, heat stages, r-22, Puron, multi zone, blah blah blah.

Mine is OK for now but is sucking down the gas. Would it be wise to wait until spring?

Any practical tips on not getting screwed (besides get 3 estimates)

Is it pretty much you get what you pay for or is there diminishing returns with more features and more to breaK?

I'm in Northern Virginia.

Thanks

Mine is fucked too. Might need a whole new HVAC from outside air conditioner (should still work even though it's older than I am) to internal furnace + blower (basement flooded, rusted the internals and shorted it out).

If it was that badly damaged and old, I'd be worried about Carbon Monoxide leaking.  Odorless and deadly. Mine is just costing me a fortune in the long run.