I have bought and sold concert tickets on ebay many times and have never had a problem.  Not only was i able to get rid of some my chemical romance tickets i didn't need but went to V this year for 50 quid for the whole weekend (half price and i saw radiohead play creep!!!!!) the foo fighters for 8 quid (less than a quarter of the original price) and this time last year went to see the white stripes in blackpool which was the greatest gig i've ever been too.  If i'd listened to any of those miserable moaners writing 'don't buy tickets' guides i'd have missed out on all those amazing experiences.  I've never written a guide before but i get really annoyed by negative people trying to stop people seeing their favourite bands, if you really love the killers then they probably are worth 100 quid a ticket because nothing can compare to watchig your favourite bands live, the feelings indescribable.  If your still worried buy them on your credit card and you can always try and get the money back if it does go pear shaped  - for gods sake live a little and don't listen to the moaners