As vendhin said this will not happen. Of course it sounds like a good idea, if I use another example to describe this its like buying a videogame, playing it and after your bored of it you "refund it" and buy another one for no additional cost. Stefan needs money to be coming from somewhere and if you could refund your guns there would be no need to pay for anything.

If you don't think you'll use a gun or are unsure, wait and see others opinions or don't buy it.