You want a cheap ARM development machine to test your packages? You can actually have one for free (both as in beer and as in speach :)) provided that you have a not to slow i386, AMD64 or PowerPC computer. The solution is called QEMU, a generic and open source processor emulator which can emulate i386, x86_64, ARM, MIPS, PowerPC and Sparc systems.
Running an Athlon 64 3800+ the emulated system is around 20% faster than the popular NSLU2 and possibly with much more RAM (my emulated system has 256 MB of RAM).
Note: I have written this howto very quickly, so there are probably some mistakes. Comments are welcome.