Different bike options to chose from

Question

Hi! I am in Atlanta for vacations for one month, and was willing to rent a bike for this period to get around in the city and exercise --- but found nowhere to rent, so I thought of buying an used one, and then maybe resell it later. I am most used with mountain bikes, and train twice a week back home (~25 mi. / training).
However, I don't know much about models. I found these five ads that interested me. Which do you think are better deals (in terms of bike quality and reselling potential)?

Bike- Folding Magnesium Bicycle unused
http://atlanta.craigslist.org/bik/1248127220.html

bicycle for sale
http://atlanta.craigslist.org/bik/1244028678.html

trek mountain bike
http://atlanta.craigslist.org/bik/1244014091.html

GT ALLTERRA OUPOST MEN'S BIKE!!!
http://atlanta.craigslist.org/bik/1237265981.html

Tony Hawk 26" 21-speed mountain bike
http://atlanta.craigslist.org/bik/1234213904.html


Thanks a lot!

Answer
Hey,

GT by faaaaaaar! Get that one if its still for sale! Thats a great deal and GT makes great bike (also good for resale)!

http://www.mtbr.com/cat/bikes/bike-rigid/gt/1999-outpost/PRD_350455_99crx.aspx REVIEWS

http://buffalo.craigslist.org/bik/1205126903.html ...Look how much you can resell for!