I never considered buying a CNC router ready made. For me the interesting bit is to make it and improve it.

Remember when working out the customs charges that they charge the 20% VAT on the value quoted on the customs form, which may well be a lot less than what you actually paid! This happened to me with the X axis rails and ballscrew that I bought together, but the actual amount charge was only a couple of percent of what it cost me.

I'm pretty sure it would end up cheaper to make a similarly capable machine yourself, especially if you're careful with the choice of materials. For instance if you can get away without using aluminium profile that will save a LOT of money. You should certainly buy some of the bits from china/hong kong - spindle and linear bearingse.

You could use the router to cut much nicer joints on the sides of the box. Fingerjoints, or even dovetails are quite easy if you can fix the wood on to the end of the bed 'vertically' and machine the joints with the corresponding cutter. You don't need much travel to do this. You don't actually even need cnc for that...