Hmm, looks like the same seller. Not sure why the ebay one is half the price.
If you must have the GM shop manual then
look here
If your ok without that then
these are much cheaper
ROFL!!!! I got mine off ebay for $55 and they are BRAND NEW.
Hynes sucks....go gm factory manual if you do the work on your car yourself. Diagnostic trees, and all the info you could ever want. I love mine. For the cav, my 95 dakota and I think I still have my 86 caprice book somewhere. If you want an awesome source of info for a yearly fee look into all data.
I have a Haynes, but it's only so specific with certain things, so a shop manual like that would be so much better.
Yes, the shop manual is an excellent resource and definitely worthwhile. Keep your eye on ebay... cheaper ones come up all the time. I got my set for around $40 shipped.
Google "service information home" (in quotes). You will get the old eSi that GM uses... everything in the factory service manual. No need to purchase anything.