Yeah, I'd meant to write more, but I was on an ipad which was taking a hissy fit, and stopped allowing me to use numbers or punctuation just at the end of that last post.
It's currently about £5k on a 110, which I think roughly breaks down to £2k for the chassis and £3k for labour and other parts. So, basically if you're going to spend £3k on labour, then it doesn't seem to me to make much sense to save the £1k on a non-galved chassis - a bit of a false economy. Of course that all depends on budget and available cash etc. what seems sensible to one person might not to another.
It's also really worth checking what type of chassis any garage uses. When mine was done - must be about 10 years ago - a mate had his done about a year earlier. Same garage, just a different chassis supplier. They were really different. Mine hasn't lasted well, thought it's obviously well past any guarantee period - his looks as good as it did going on. There are two well known suppliers, and I can't remember which without checking the paperwork. But, if you go down this route, definitely be sure you are choosing the chassis you'd prefer. Maybe I just got one from a bad batch.