It is far cheaper to come to London than Japan under general circumstances. Hotels and or places can be pretty cheap, and actually quite nice if you look around. I've been to London and stayed in a few London hotels, so I could say which ones I think are good and which are not so. Most people on here from the UK are already there or thereabouts as far as London is concerned, so that's why it'd be best there. And since London is the capital it's easier for people from Europe to come here. There are, as far as I know, way more American people here than there are us lot, so arranging your own meet-up wouldn't be difficult, although America is a lot bigger so you guys are more likely to be spread out more.
In any case, if you can't manage the costs then fair enough, but London is probably the most practical place for us Europeans
