Even the cheapest thrusters are well over $1000 with a speed controller. The F5 Robotics 5BL http://www.f5robotics.com/
Each thruster is tested before shipping and includes a high torque brushless motor, dual shaft seals, oil filled chassis, carbon/epoxy rotor and ABS housing. With no metal parts exposed, maintenance and corrosion issues are eliminated.
F5 also has a large and a compact ROV frame kit to compliment the thrusters or to be used with your own thrusters. Their proprietary control units are also available complete with LCD screen, joystick controls and tether.
Their Prospector ROV units will be available this spring as ready to use units and the Prospector Jr. Is available now. The Prospector Jr is a 2 foot ROV that arrives ready to use and is less than half the cost of conventional ROVs. More details can be found at www.f5robotics.com/