Upgrading the drivetrain is a pretty low bang for your buck. It will save some weight, but unless you’ve got to have electronic shifting, very little difference in performance.
First place I would put money towards is the suspension.
Have to say, though… if you are buying this bike and then immediately upgrading the drivetrain, wheels, and whatever, it begs the question of why not get a higher level model to start with. Buying a decent bike and then upgrading it to a very nice bike is the most expensive way to get a very nice bike.
Also, are are there some things you can pull off your current bike that would be an upgrade over the new one?