my balancing plug wire disconnected from my battery what should i do?

i was thinking about just working out some sort of trade with my LHS and pay a lower price for a new one

It's iffy at best but if you can get the case opened and maybe carefully solder it back on. I don't recamend doing that unless you are good at that kind of thing.
You other idea is good also if the hobby shop will do it. If all else fails, contact the batteries manufactuer and see if they will do something.
Good luck man.

if it was a soft pack and you could see the wires
i would say give it a go. but unlesse youve pullled
a hardpack apart and are 100% i would take it to
someone.

If that's an SMC pack, contact them via their website and ask for a replacement or credit towards one.

Unless your confident in your soldering skills don't test you luck.

Excactly my point. I consider myself a decent solderer(is that a word) and I wouldn't try it.