A fine question - dunno.
I would think upgrading to X2 now would be a fine thing. I am confident that it will be less to upgrade from X2 to X3 than from X1 to X3.
Additionally, X2a is a fine product, and you may choose to upgrade to that now and then try out X3 as a demo, prior to purchasing that upgrade - just in case there are any snags with X3.
Just make sure your system meets the requirements for X2a first, in any case.
Bob Bone