In a story in UPI-Beta, Manchester Police who raided a criminal gang's hideout scooped up a 3-D printer and a host of parts that were said to be gun parts. The UK police have been up in arms over reports of printed guns made with the new and cheap 3-D printer technology. If this becomes a real threat, their handgun ban isn't worth the paper is was printed on. Making a real gun on 3-D printers is a real challenge, as it is hard even to make a decent water bottle cap that doesn't leak.
A 3-D printed gun from Defense Distributed
In the end, this was all moot, as the printed parts turned out to be more 3-D printer parts themselves, according to GigaOhm's blog. It was also reported that the street price for a real gun was around 200 US dollars in Manchester. I'd go for the real gun.