Anyone know anything about electric violins? I'm looking at a few second hand ones, but I don't want to spend more than about £50 (GBP) ... there's a stagg and a couple of carlo giordanos that look like they'll end up around my price bracket but are they gonna be really crappy for that price? :/

If they are crappy, anyone know how easy it would be to change the pickup to a better one?

I would look at it that they are SO cheap, that it's not even worth changing the pickups. When you have enough money to get a decent set of pickups, you could just buy a whole new violin.
Now 100% humour free, in accordance with the rules.

I agree with fleabag, however you may just want to get it o see if you like it the cinsider it in future? (You made me want one!)