The first thing you should think about when you are considering getting a tattoo is that it involves someone sticking needles into you.
Now, who do you trust to have enough respect for cleanliness to keep the needle in you? Your doctor, maybe, but who else? Some, greasy men leering at a tent at an outdoor concert? your friend's buddy, who works out of his basement? No and no.
You believe people who act very much like a doctor when it comes to cleanliness, and no one else.