mobile

I am just getting into ROM development, but cannot really build anything due to my only computer being a laptop (a build of cm12.1 took probably around 4-5 hours so far and still isn't finished). My friend is letting me use a server to build on (chicagovps ssd-cached enterprise), but it only had 2GB of RAM and a 50 GB SSD. Not really great for building ROMs. What do you use for your ROM building, preferably something pretty cheap? Thanks guys!