Don't think about the house in the key primary school film, which is generally not less than 2w5/ m2. In your present condition, it's better not to think about it for the time being. After all, it will be at least eight years before your child goes to school.
The budget of 80w is not low, but it is not easy to buy a good house in Tianjin. If you have a local hukou, a price-limited room is a good choice. The average price of price-limited rooms is below 6000 yuan. Although the location is a little different, it is almost the only choice for young people with poor economic foundation like you.
If this 80w is all your savings, I suggest you choose 60w, because there are many uncertainties in life. Don't put too much pressure on yourself, just like someone borrows 50w to own a house and a car, but the pressure behind it is definitely great.
Anyway, if the funds are not rich, then choose the three districts here, Hedong Hebei Hongqiao. Compared with those three districts, the house prices here are not too outrageous. Find a second-hand 60 square meters with a better environment and choose a 70w menu.
Please look according to this standard first, and then consult if you have any questions.