I have went there recently.
2 dishes $3.8 and 2 dishes $8.8, total amount is about $29, so it is approximately $3 茶位per person.
The food is ok, but not reach excellent standard. However, with such low price, it is worth to try. The most important for me is i can take a rest since it is very tired after walking around in ShenZhen. As least, you do not need to pay the bill and leave immediately after consuming your food as you are in fast food restaurant.