Where's Pat?! We need him here stat!
Sorry. Life keeps happening.
Previous gen MacBook Pros (the ones with the boxy corners) have the power adapter port as part of a larger assembly piece which is not all that cheap (compared to, say, a MacBook's little magnet block). It's that part that would make the repair more expensive. If the damage to the bottom housing is just cosmetic, there's no reason why something that got bent
in can't be bent back
out again (making enough room for the previously mentioned assembly piece to be replaced). That's if you want to be able to plug the MagSafe back in again. The Apple store won't do body work for you, though.
Another possibility is to use an external battery charger. Remove battery, charge it, reinsert it, run it down, repeat. It's a great solution if you can get everything done on one battery charge (or if you buy a second one and charge one while using the other). Putting the computer to sleep while you swap batteries might get kind of annoying, though.
Regarding a new unit: Hard to say what to recommend without knowing what it is you want to do (and I mean specifically what you do, like what programs you run and how often). The new MacBook Pros
do indeed last a looooooong time compared to previous. I'm happy to make more recommendations via PM, but I tend to check in only every couple of days this time of year. FWIW, I'm still running my Titanium PBG4 from 2003 as my main laptop. It lasts between 2-3hrs on a single charge (on the original battery!)
unless I'm on WiFi. Then it's about 1.5-2hrs. It still does what I need, even if it doesn't do it as fast as I'd like.
tl;dr: Repairing your current MacBook Pro is probably the best option depending on which model it is
and whether the new ones are significantly better at doing whatever it is you do to make up for the price difference.
--Patrick