On the HG issue I wouldn't worry too much about it. Very few 'cruisers have had HG issues. You should get a compression and leak down test done anyway (you are having a reputable mechanic check it out, right?), then you can pretty much be sure that there is no HG issue.
Locally to me there's a triple locked '96 LX450 that's a "poser" vehicle (nice new knobby tires, damage multipliers, etc). Asking $10k for it, but it's only got 145k on it, and I think they'll come down to $9k (at least, might push more). So $6-7k sounds a bit high to me, but a lot of it all depends on where you live.
For the rest of your questions, check out this post.
IH8MUD.com Forum - View Single Post - FAQ for 80/LX450 - April 26, 2008 - Added leather replacement w/ links to seat heater