Never seen a 106 GTI that cheap, that's more the going rate for a 106 XND or something.
Volvo 700 series?
There have been a couple near £500. Not been in very good condition though and up for a quick sale for whatever reason.
Someone on the forums managed to get one for £700 in really good nick not so long ago iirc, such a bargain. Owner didn't know what it was worth. They are about, just need to look hard enough.