when my 3g was new it was fine, but i used it so much after 8 months i had to take it back, it would randomly shut off and wouldnt hold a charge. I got a refurb with a bootloader of 5.08, means any baseband can be downgraded to an unlock. and it seems to be just as good as a brand new one.
even my ipad is a refurb, it had the yellow stain on it for a few weeks, got it replaced and the refurb is working just as awesome.
refurbs arent bad at all, or used ones either, apple has a high standard and you can easiy save 50$+tax probably around 70-80$! penny saved is a penny earned, use the extra money for a case and screen protector.