if i was you i would hold out for a 2B, they usually go for around the price of a new x3 with comparable envelope, but don't come up that often.
the 2a is a lovely lump of good ol fashioned iron and although their travel is seriously limiting there are ways around that
i have a centec 2 in the shed, its one rigid little bugger but it would really benefit from a table transplant (hmmm X3 extra long table + centec 2????)