Depends on what they are...
Let me share with you this dilemna...won an EBay auction quite pricey.
The bloke emails me and says "You need to add $40 for Paypal"
Not disclosed on the original posting, in fact all that was posted for payment was the Paypal logo "This seller prefers Paypal" "Will ship worldwide" etc..So at that point do I forego the record and suggest the guy engages in a little sex and travel (in two words), or do I bite my tongue and pay the "extra"? I am afraid I bit my tongue in this particular instance as it was a rare 45.
As far as I am concerned PP is a cost of doing business for the buyer, and I considered myself hard done by by this non disclosure. So I left no feedback, and the guy chased me up about it too - by which time of course the record had arrived safely "chez moi", and I was able to tell the dealer precisely where to stick his missing "positive feedback".