There has been discussion on MN before about similar units, sometimes seen on Ebay as aPad or ePad and at similar prices (but in US$ being sold over there). Suggestion was that it would be fine for under 10s but is a bit dated (Android is now on v2.2, this seems to have v1.72 installed and might not be upgradeable).
I think it really depends on what your 16yo would be using it for, whether it might be used for school work etc ?
In Asda Living, only yesterday, I saw an HP 10" screen notebook, named " Mini 110-3102 " at 237 pounds.
Sorry if that is too costly, but it is a Windows 7 system with cut down versions of MS Word and MS Excel (MS Office Starter 2010), so for a teenage student should serve quite well. HTH.
PS If Asda has sold out, Carphone Warehouse has the HP Mini 110 at 239 (worth asking about the Microsoft Office software in either store to check it is not just a 90 day demo copy). I don't have this model but felt it might be of interest (and should be trendy enough not to be ridiculed by teen peers).