You can edit your auction and put a number up that will let a person purchase an item instantly if they are willing to pay the credits. You can also change it to free shipping with the edit tool.
A little help for you here--- It doesnt really matter what people Say they will bid-- people can bid 1000's of credits-- it all depends on what the last bid entered is, as to who wins the item, and for what amount- - -
example-- you start the bidding at 100. . . Bidder A bids 300 credits, it will only show 100 until the next bidder bids--- Some one could win this for 200 credits if no one over-bids them- - -
People cannot give you credits for shipping-- there is no way to transfer credits specifically for shipping. . . So people can SAY they will give you xx amount for shipping-- but in the end it all boils down to who is the highest bidder. . .
Also-- regarding shipping--- you could wrap this up and send it in a Priority mail flat-rate padded envelope for about $5.00. . . I dont think it would fit in the small flat rate box. Hope this helps you -- at least a little bit!
remember-- no matter what people say to try to bargain with you-- its the highest BID that Wins!!