IIRC, larger rings and pistons cost the same through engine builder, so the added cost to the rebuild is what the machine shop will charge. Having the block bored shouldn't be all that much, it is easier to do than the head.

The $1500 in AK seems a bit high, but then again it is AK, the shops there kind of have you over a barrel.

More than tread lightly. Leave it like you were never there, nor anyone else.
'90 X-cab 4.88's 33 BFG AT's, rr ARB, Headers, Ignition upgrade, cold air induction.
'91 X-cab 5.29's 315's BFG MT's, rr ARB, custom bumper and flatbed