the market there is pretty limited. I can't really think of anything that fast that cheap.
If you look around, you could probably find an slg, azodin blitz.
What comes to mind though is an ION. I shot one for a while, and I bet you could find a used one in fairly good shape for a hundred bucks. The speed is almost there, the stock board is capped at 17, and with a trigger upgrade that is certainly possible in semi. They are also VERY customizable, literally every part can be exchanged for something aftermarket. They are also good shooting guns, and are quite quiet and fairly efficient. If getting around the maintenance issue is feasible for you, I'd recommend one.