For the money I'd opt for the TREK. $100 is a good investment to make on a previously owned bicycle if you're buying stuff to make it fully functional once again as well as safe to ride.

Likely as not, spending = $$ on a new bike won't bring you an = ride quality. Besides that, resurrecting something someone else's tossed to the curb brings some gratification in the doing as well as whatever eventual pleasure you get out of using it.

And you'll learn some things along the way, maybe even something new to you.