so around £4000 for full colour printer.

If you're thinking about getting one - bear in mind that for some things they are brilliant, for others - not so useful.
For artistic models, fivurines, extrdued photos etc - these are unbeatable for the money.
For small or intricate models or things with interlocked or moving parts - not so good.

Over the last 2-3 years the odels they exhibit at shows have improed immesuarably. These days it's hard to tell the difference between a mcor full colour paper mache print and a full colour stratasys objet print - given that there is a 10x price difference between the two systems. The mcor setup is impressive.