The Jabo Radio Controlled Fishing Bait Boat is probably the cheapest commercially made bait boat on the market.
The Jabo comes in two different versions with the upgraded version featuring a builtin high spec fish finder. This comes with an LCD transmitter instead of the standard one that displays lots of information sent back from the boat.
The Jabo bait boat is made from strong plastic and is completely sealed to ensure no water can get inside, even if it turns over. If you're using it in very wavy conditions and the boat did capsize, it is designed to turn itself the right way up again. Another great feature of this boat is that the propellers are actually on the inside and protected. This means that even if using in weedy water the boat will never get tangled up.