I bought my Frontier Elite from Mac'sBBQ...
http://www.macsbbq.comIt was £250 all in for the unit, 2 bags of smoking chips and 5 day courier delivery to Northern Ireland. They seem to be the official distributor of ProQ products in the UK and I have read nothing but good reports of them on here. Although I haven't had to use it, I hear they have excellent customer service as well.
Unless your Ebay find is second hand, I would be wary of mega deals like that. Personally I shop by the mantra "if it's too good to be true, it probably isn't true". Although if you do go for it, make sure you pay by PayPal so you get their fraud guarantee.