I'm looking for a fast 25-30" aerobatic FPV plane similar to the Theory but without the $300 price tag.

I'm an experienced builder/flyer, beginner mode electronics not needed.
I can cut/cover/scratch-build a hotwing, but spare time is in short supply, would prefer an airframe thats rtf.

Suggestions?

Nano Goblin on 3S may do it for you... You would just need to add camera and VTX for a basic FPV setup. There's a whole thread for that plane in this forum.

Nano is a huge departure from the Theory wing. A better low cost comparison would be Eachine fury wing or the Sonicmodell F1 racer. The fury wing, IMO flies MUCH better than the Theory(have flown both), but the wings aren't as strong and the magnetic locking tabs leave a bit to be desired. Still, I am building three right now, one is the PNP , one will have a cobra 2217 2300kv, and the other should really scream with a Scorpion 2221 2580kv motor.
The PNP version is right at a 100mph wing as it is, btw.
I just also ordered the sonicmodell race wing. I think it will be faster than the theory wing, but it wags a little more and has a tendency to high speed stall, and the PNP version has crap servos. Still, it uses the same motor/esc as the Fury wing and is only like $80 shipped.
Fury wing PNP, just ad rx and fpv gear:
https://us.banggood.com/Wholesale-Wa...l?rmmds=search
Sonicmodell F1 PNP, same deal, but also replace the servos with something better, like EMAX ES09Md:
https://us.banggood.com/Wholesale-Wa...l?rmmds=search