If you can generate more funds in the following weeks, and you dont have a Book now, I'd recommend getting refurbs and try not to spend too much on upgrades. Save as much money as you can as you wait for the updates. When the Montevina books come out, sell the refurb you just got and with the money you saved, grab a Montevina book (you might even have enough dough for a Pro if you save well).
If money is tight, waiting would be the best option.