Should I be worried about my rare lands rotating?

So it seems that in September a lot of the fast lands and all the pain lands will be rotating. Its still awhile away, but I don't want to spend a bunch of money on lands that will rotate out that soon. Should I wait and see what lands are in the next set, buy the lands I want now, or just spend on the fast lands/verges/creature lands/surveil lands that I know arent gonna rotate out? I've been wanting to make the esper pixie deck, but that uses a lot of the fast and pain lands that are gonna rotate, I also want to get the lands for dimir bounce.