As dc42 mentioned, going with a 32-bit smoothie board is an option. I thought I saw an Alibaba clone for $50ish in the general thread (under Smoothie Hardware Alternatives). It should last you longer at this point then the Arduino + RAMPS, though with a cartisian printer like the i3 you are probably fine sticking with the 8-bit platform.
Sorry if I confused you with the Arduino v. Freaduino comparission.
If this is your first printer, depending on how much you have invested so far, you might be better off purchasing an established kit. All the components come from one supplier who can send replacements if something is defective. Single point of contact for support. And you get the experience of putting the printer together without facing the seemingly difficult questions such as which board to purchase. Often buying individual parts from multiple sources will cost you almost as much as a kit, especially once you figure in shipping and handling plus any import taxes.
Sorry if I confused you with the Arduino v. Freaduino comparission.
If this is your first printer, depending on how much you have invested so far, you might be better off purchasing an established kit. All the components come from one supplier who can send replacements if something is defective. Single point of contact for support. And you get the experience of putting the printer together without facing the seemingly difficult questions such as which board to purchase. Often buying individual parts from multiple sources will cost you almost as much as a kit, especially once you figure in shipping and handling plus any import taxes.