Well you can't complain about the price of the Lujji (£35 - £40 from Amazon), Afraid I don't know much about the Chinese makers but I think there may be a link between Lujji and the Igo Primo, as Primo is mentioned in their documentation, the problem will be support (or lack of it), so you probably won't be able to up-date the maps etc
Hey thanks for taking the time to reply. It looks pretty cool like the ones I've seen on this sat nav review site http://bestsatnavs.co.uk/cheap-sat-navs/
they look very similar, ie a rectangular screen and not much else which does actually look pretty cool i think. But I've yet to talk to anyone who's actualy used one of these cheap sat navs and I'd be wary about how well they work and respond etc
The thing that makes me think these units are all based on the same device, is that the Lujji, Igo Primo, E-Plaza, Excelvan etc. all run Microsoft Windows mobile e.g. WinCE