You are missing the engine size (4 or 6 cylinder), that will most likely impact labor costs, but the following are probably decent estimates of the work you have listed (parts & labor totals)
Timing Belt & Water Pump = $450 - 700
Upper & Lower Radiator Hoses, Thermostat = ~ $300
Rear Brake Job (Pads, Rotors, Flush) = ~$250
Transmission "Change"? = Could vary....probably at least $900 - $2000
So that total = $1900 - 3250
If you need a new transmission on top of all this other work, it may not even be worth keeping the car. The timing belt and water pump are usually a 60 or 90,000 mile tuneup. If they were never done on your car, it's likely you have other problems, especially if you are at high mileage. If you transmission is gone, that's unfortunate, but this job could be costly. If you can't afford a new car, or a reliable used car for slightly more, do the work.
Consider buying parts on you own, it's typically cheaper, then bring them there and just pay for labor...at least for the brakes. The timing belt and water pump are MOSTLY labor costs. The cooling system work is just maintenance.
Good luck, and don't forget to keep those tires properly inflated and have your oil changed periodically.
