Well in the OP defence I'd say a lot of couple have spent €200 a week on entertainment, a couple of meals out, a movie, maybe a concert... its easy to rack up.
My tuppence for what its worth, I'd say see if you can both save €1k each per month for the next 12 months... that will get you to about €75k mark in savings, which is a significant deposit on your €300k house, and gives you wriggle room for furnishing / kitting out, without having to depend on credit.
I'd also agree on putting in place an agreement at the start on what happens if it all goes wrong (hopefully not, but...). Define now what would happen, would you buy her out or she you?
Also check what would happen if you were to start a family in the next 2-3 years, can you easily service a mortgage on 1 salary?
For the rest, good luck to you both.