3040 size router plans?

[BigAl]

I'm toying with the idea of 3040(ish) (300x400mm work area) size router, and was wondering if there are any good plans around anywhere?
Main use would be for doing plastic enclosure cut-outs, and possibly some aluminium work (ok, would most likely be very likely if I build one!).

I'm just looking at an idea of cost, as I know I could buy one for £700ish prebuilt and then tweak/upgrade/pull hair out from there, but would like to price things up to compare costs.
I'd also be interested to hear costs from those who've built/bought something similar (feel free to use PM if you don't want to post in public!)

You can come and have a look at mine built to my own design that was inspired by the Solsylva CNC routers.

I'm probably 30 minutes drive from you.

Cheers, BigAl.