Like anything else on eBay, there will be the occasional great deal but also some amazingly overpriced knives.

I picked up one screaming deal on a Busse but you have to be patient and know your strike price.

Focus on a couple of models that you really want. Watch the market on BF and eBay for a while and get a sense of where the pricing sits and then don't overbid.

Generally, although you have to really quick, you will probably pay less on BF.