Definitely the hardest-learned (and sadly, most-often learned) rule I've found in this hobby is "you get what you pay for" and the corollary, which is don't buy something you don't think is worth a damn when you buy it. Get good quality items you can build on.
For example, you could throw less cash at a new [insert POS type of recorder here], which will likely crap out on you and generally function poorly to start with. Or spend more and get a used/new higher quality deck like the M10 or R-09HR. Now, down the line, you may decide you want a better deck than those, but either of those decks are certainly capable of being a decent component in even a fairly top-of-the-line rig. Certainly, they aren't a waste of money, they aren't garbage, and as a result, they hold their value to some degree and will sell better used.