So my girlfriend's laptop's motheboard short circuited and the new motherboard would cost at least $250. Thinking that isn't really worth to invest in a two-year-old laptop, we're considering getting her a new one.

So my questions are:

1) Would it be safe to buy one from ebay?
2) What brand would you recommend (besides IBM, because those are too expensive)?
3) Around a budget of $450 MAX, what would your best recommendations be from the listings on ebay?

I'll +rep anyone who cares to help me out