How expensive can the property be?

Hello! I would like to ask how high the cost of our property may be without making significant sacrifices in quality of life. In summary, unfortunately I have little equity, but I am a civil servant with a secure income. I came across a 300 sqm plot that should cost 100k including development. How much "may" the building cost? Thanks! General information about us: Our age? 32 + 32 Are there children? 1 baby Our professions? Civil servant + housewife (because of baby soon) Income and asset situation: Household income (net)? About 3100 EUR, wife without income How much child benefit is there? 204 EUR How much equity do you have? 30,000 EUR How much equity do you want to put into the house project? 20,000 EUR Expenditure situation: Housing costs: 800 EUR Other living expenses: 800 EUR Available intermediate budget: 3.1k - 1.6k = 1500 EUR Not included costs: Costs for the baby: ? Car repair: ? Legal protection: ? Furniture: ? Vacation: ? Furthermore: I still have to repay a Bafög student loan, total 8,000 Euro, monthly 130 EUR.

Financing 380k€ with your salary... Have 200€ more ... With us it became a bit

How much equity did you have?