Dog's broken leg question

Hi all,
In one of the freecycle groups I frequent, a person is trying to find a good home for a 3 yr. old Chihuahua. I happen to know a couple who've been wanting one but since they don't have access to the internet, I'm trying to be of help. I've emailed the person & am waiting to hear if she still has the Chi but she stated "Her front right leg was broken a while ago and it was not set correctly, but she gets around real good on her othere three legs". This has raised some questions for me. For example; can a dog like this go on living this way & not cause further damage to its leg? or should it really be taken to a vet for surgery? I have never dealt with any pets with broken bones or needing surgery other than Aggie's neutering so I am clueless. Also, if you've dealt with this sort of thing, is it a really costly procedure? I know the couple who want it may not have the funds right now for an expensive vet bill but otherwise will give it a loving home & give it proper vet care. Thanks in advance,
Gemila