chevelle and elcamino ss what kind of money?

alright guys looking for a little help. i had a 71 ss chevelle and sold it about 13 years ago and know i am in the market again to get back to my roots. i know this barret-jackson auction on tv has helped the price go up on these cars. i need to know what to expect when looking at some cars, prices to see and prices i should offer. by the looks of things you can almost always get your money out of these cars if needed to resell. i'm looking at 71-72 chevelle and elcaminos.
basket case, needs full resto and dosen't run-$$$ what's it worth??
untouched car runs, but needs resto-$$$ what's it worth??
somewhat restored, but no frame off-$$$ what's it worth??
frame off resto, no i know big money.
how much is a bb worth then a sb????
how much is a 4spd worth more then an automatic????
a/c???
with build sheet and protect-o-plate???

is there any rule of thumb or guide lines on prices i should follow, or is it just market price out there now???