Can't really see a problem with it. If someone wants the goods to be sent to him, and agrees the postage costs before and is willing to pay for it than why not. Can't assume that if someone wants You to post goods to Poland is equal with trying to run a scam on You or something similar. You'll get scammers in every place on earth and I never had any problems when sending stuff abroad, only twice someone from UK bought something and never paid for it.
About the interest with mobiles especially fancy ones. Everyone likes nice toys and as exchange rate of Polish Zloty to £ is not doing any favors the price in UK for some goods does. You will sell a fancy expensive mobile here for less as there are probably quite a few of them up for sale as You only need to take a £20-30 contract to get a top of the range model. In Poland on the other hand when You want a nice handset than You either pay very high line rental or pay a normal line rental but pay loads for the phone. My mum was on a business plan and was paying £60 a month (using current exchange rate) and still they wanted her to pay about £50 to get a Nokia 6230 (it was few years ago)
Plus if You're a technology geek and You need newest shiny stuff than unfortunately You need to shop abroad as the launch dates for Poland etc are always later then here or lets say Germany.