^^^ agreed. I've seen many, and purchased a longblock as clean as they come for 600ish shipped.
@Kyle Chandler has a clean shortblock for 300 right now.
61x cases-about 50
61x cylinder-100-150
Bore-100-140
Pistons-100-200,at least a year ago there was still a large supply of 82.5mm sudcos for 50ish/kit
Crank-300 for sbt or 450 for oem rebuild, mint used is an option too..
Seals+gaskets+sealant+misc hardware=~100
A few hundred more pretty much guarantees years of life. Buying a 30 year old motor is a gamble especially if you plan on modding it. Could work out absolutely fine though. (I've personally had a crank go on an old 701 so I may be more preventative than some, but losing a nice top end to a worn out crank sucks!)
@LIVE2RIDE Powersports has had mint 61x top ends for a good price that could save you a couple hundred or so instead of fresh bore.