Costs very widely based on what you are looking to do, who you want to do it, and what format you want it in.

Every project is different.

Do you need lights, seperate audio person, wireless mics, tripod, dolly, etc.

Your best option is to put together what you want to have done then call around to different video companies.

A kid with a video camera might work for minimum wage while a production company could ask for $100-$10000 an hour depending on what your needs are.