Sell apartment and purchase fixer upper, advice?

My 2 cents and everybody is different...but location is top & one thing you cant change no matter how stunning the house maybe. We moved to a beautiful house in a location we didn't know. Right away it wasn't right for us. We sold less than 2 years later for our ideal location, to a reno job. Now we got lucky with being able to rent for 5 months nearby while we reno'd it and had a good trades who completed everything on time in 5 months...not a full gut job but almost everything but sub-floors/roof, you couldn't live in it while work was going on. I project managed it & kept everything running on time and stuck to our budget. This was just before March 2020, costs have spiraled since then, but location situation will never change! Only you can decide how important location really is to you.
 
€27k for a bathroom retrofit sounds very expensive to me.

We did one a few years ago for €7.5k, all in (including VAT). €27k must be a very high end job.
My mother has just paid 13k for a very large upstairs bathroom and 3.9k for a downstairs toilet full renovation with tiling to ceiling and floor from a local bathroom specialist. 27k seems high.