My supposed next tattoo appointment is kind of stressing me out

So my sister asked me to come with her to get a new tattoo because she was worried about going alone. At first it made no sense but then she proceeds to tell me he is an apprentice who supposedly does tattoos in his apartment. Now I refuse to go to a tattoo appointment and not get a tattoo (yes I am somewhat bringing this problem upon myself) however I am extremely worried about his cleanliness and and if he's sanitary with his products and tools. I looked at his whole instagram account, he's only got a few followers (below 100) but his work seems fine and I even noticed that there was a client that went back to get another one done by him. Another concern of mine is his prices, and the concern is that they are extremely low. He refuses to charge more than 100? Does this seem off to anyone? He's been super sweet and accommodating in the messages but I'm just scared that this is maybe not a good idea. I need to let the tattoo reddit community decide this for me 😭