I've been reading these forums for awhile now, and just registered because I'm between a rock and a hard place. If this is in the wrong thread, sorry!

I started biking a few months ago, with my Mongoose Exile, but after riding my brother's hardtail for awhile (Schwinn, Sports Authority kind), I've just about had it with my bike and it's time to upgrade. I'm tight on money so I want to get the most bang for my buck.

The following choices are:
Trek 3900 ~420$
Trek 4300 ~480$
Specialized Rockhopper ~515$ (sale)

I mainly want to ride the trails in mountains, but I've really gotten into going on the road as well for the "shorter" distances (20-50miles). I'd say I ride 2/3 road 1/3 mountain. I don't want to get a roadbike as it seems like ill get a better deal with a hardtail for it's price. (Better starting hardtail as opposed to a roadbike and I'm a clyde so roadbikes seem fragile to me).

I'm thinking that cost more = better parts, but is the 100$ difference between the trek 3900
and the rockhopper noticeable and worth it? is my main concern.

Thanks for the input.