so to bring this thread to a conclusion for the archives...

i purchased the 750 for $150, 19" frame in reasonable and respectable condition, seller was asking $250 in the AD but we were both satisfied with the agreed upon price, he was also a bike enthusiast who seemed happy it was going to someone who specifically appreciated it.
here in the northeast metropolitan area i see the 700/720 trek models averaging from $175- high $300's depending on condition, even higher for sellers who are fishing with mint 750's
the 700's/720's appear quite a bit but 750's not as often and i have yet to see a 790.
as "wrk101" points out distance from buyer to seller has a lot to do with how quick the bike goes, i drove about 1.5 hours and i do believe the bike was listed for for at least a few months.
if it were spring/summer and in a less remote area I'm sure it would have gone pretty quick.

i am still reasonably new to the game so what specific components/parts on these treks are considered more sought after or desirable?
i see certain derailleur/crank-set names or brands being referred to someties

thanks