[jodi]

Personally, I bargain a lot. I won't bother if it's one thing for a quarter, for example. But if I am buying multiple items (i.e. kids clothes or books) I will almost always round down and ask the seller if they will take less - like if I have 5 items for $.25 each, I'll ask if they will take $1 for all. I bet they say yes 95% of the time.
If I'm buying something for $5, I'll ask if they will take $3 of $4 for it, even if I would actually pay $5! It never hurts to ask and I can always pay full price if they say no. I can't personally remember anyone ever being offended by my asking, even if they do say no. I think most people expect it.