I also find this constant "you earn too little, find something new" out of place. The situation is as it is. And this is about opinions on a specific situation. Whether someone in Frankfurt earns X€ more per year is a completely irrelevant piece of information for the (currently increasing number of) OPs. In the end, only dissatisfied people leave the forum again, who daily wonder if they might be underpaid. Personally, I find €2,600 net at 27 years old very good.
On Topic: I find the rate of €950 + additional costs somewhat high given the total income. But it also depends on when your wife starts working more again.