If you're going for the achievements you can always wait till you get some items worth 100mill for collate and just have someone buy them/you buy them back. If you want to spend your sp, do it.

XD I'd take that out! I keep all my moneys in my vault anyways :3 Get some interest off that!

If you seriously want the achievement, no. If you'r not interested in that, take it out.

Well personally I'd say leave it in the till you'll get the achievement eventually. Not to mention I would be willing to help you get it but only have 54 milion atm. I went on a shopping spree myself the other day.