I prefer to buy mine used and support other mothers. Sorry I can't really help!
i'll buy used if the used dipes are priced like a used dipe. you can get a new FB with New insert and free shipping for around 13.50 if you buy a small package of them. I don't like wondering if the used dipes will have repelling issues, buildup, bad elastic, stains....The most i'd pay for a used FB is maybe $9 or 10 IF its in EUC with NO issues. I've been burned by crappy dipes too many times