Can't tell from the pix: Does it have a full Z axis? If it does not you need to figure in either the cost of adding that or the cost of a stand-alone THC with lifter.
A lot depends on what you can keep and make work. If you are comfortable in electronics and CNC it might be a really cheap way to get a plasma table. It also might be a money pit.
The controller may need to be replaced; especially if it is not PC based because there won't be an easy way to integrate the added stuff you need into a closed controller. There might be "stuff" in there you can use but don't count on it.
Bottom line is you can build a 4X 4 plasma cutter table with full electronics including a THC for around $6,000 (less if you can weld and scrounge materials). You could spend half that (worst case) on just electronics you need to upgrade that table, so if you pay more than a couple of grand for the table you stand a chance of going upside down.