1) Bite the bullet, dig out the credit card and go for it!
Absolutely! FWIW, I've pretty much come to the conclusion that the best action is to acquire a new machine and hope to get 2 (maybe 3) years out of it before a combination of obsolescence and desire for new toys moves it down the chain, to be replaced by another.
Thus, a brand new machine becomes my main machine; my main machine turns into reserve box 1; reserve box 1 goes to my wife (who has absolutely
no interest in a machine for its own sake and wants only a minimal, stable platform); my wife's box turns into back-up machine; backup machine goes to wherever seems like a good idea at the time (as long as that's not the store-room that used to have about 10 others in it).
Despite this view, last year I made the mistake of upgrading parts of my wife's machine and wound up spending as much on subsequent piecemeal upgrades as I would have on building a modest new box to suit her needs. A new machine would have been
better than what she ended up with and might even have cost less. In the end, I wound up stripping and junking the 'upgraded' machine and buying her an entirely new one -- you'll notice I couldn't
quite bring myself simply to toss out the whole thing,
sigh.
For me, things are moving too fast these days to make most upgrades cost effective. The pain of an intial purchase is a one-time thing. The pain from a 'Band-Aid' upgrade can last much longer.