His quote is within the accepted range for what is listed. Retail price on parts alone is in the $13000 to $16000 price range. Couple hundred shop hours and your right on the estimated $30000 mark. Understand he is not going to shop around for a bargain LS and computer. He is going to pay up for a known good unit. Same with the rear end and transmission. If he sends you home with junk his reputation is shot in the hotrod community. If you can’t/won’t do the work yourself you have to open your wallet and dig deep. Your situation with HOA’s is the same problem facing thousands of home mechanics wanting to maintain or build their dreams in their driveways or home shops. My little City has specific ordinances on the books prohibiting working on your vehicle in the street in front of your house or parking on your lawn. Some HOA’s are even stricter.
Good luck with which ever way you choose.

Martin
'62 Chevy C-10 Stepside Shortbed (Restomod in progress)
'47 Chevy 3100 5 Window (long term project)
‘65 Chevy Biscayne (Emily)
‘39 Dodge Business Coupe (Clarence)
“I fought the law and the law won" now I are a retired one!
Support those brave men/women who stand the "Thin Blue Line"! Hug a cop!
USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)