How much money do you need to start your own tattoo shop?

That depends entirely on how nice a shop you wish to start, and how many ruglations you are required to fulfill in your geographic area. Rumor has it Hart & Huntington in Las Vegas cost upwards of a million dollars to start. I know personally of another person who opened a shop with a few hundred dollars.

Asking how much it costs to start a tattoo shop is like asking how much it costs to have a wedding -- the answer lies in your own expectations of the experience and how much you wish to spend to make an impression.