Truth be told, I don't particularly think you need a super-high-end anything to do this kind of work, or certainly for learning purposes. For the most part, having slower hardware won't prevent you from doing anything, it'll only delay you (slightly). Professionals pay big money for marginal speed increases because the other per-time-unit cost of associated software and manpower is such that one-time hardware costs are easily re-couped. As it is, it sounds like you have more time than money at your disposal, so your considerations might reflect differently on your outcome.
Granted, more never hurts, but we also live in an age where even fairly average computer components are far more capable than is strictly necessary.
