The housing market is currently just as tense as for single-family homes. Sellers are still not budging from their 2021 prices and do not understand that current prices are about 20% too high. Also, if you buy an apartment that probably costs around 500k in your region, you have gained nothing. Because there you also have the high interest rates, and whether they will go down in a few years is questionable. Then you can never start building your house. If you then decide to sell the apartment, you have wasted €50,000 in ancillary purchase costs. A lot of money for nothing. Therefore, my tip: push through now and lower your expectations. No garage but two gravel parking spaces. No basement but a higher roof with 2m height (30 degrees). (That also looks okay with a hipped roof). Then you have an attic as storage space and, if necessary, a garden house. Unfortunately, more is not possible right now as it is a very expensive time to build. These three options can happen with the same probability.
1.) Buy an apartment (pay 50k ancillary costs) and build when interest rates have decreased
2.) Build a house and lower your expectations
3.) Buy an apartment (pay 50k ancillary costs) and never move into a house because interest rates keep rising, inflation eats up your salary, and you can never build again. Because building in the coming years will remain reserved for the upper class due to expensive energy / even higher interest rates and rising construction costs.
I would choose option 2, because otherwise you might have a plot but never see a house on it. Who says it will get cheaper? I believe it will at most stabilize at a high level. A purchased apartment (at currently overpriced prices, which you might sell for less in a few years) could cost you the dream of building a house. Whether it will ever become cheaper to build, nobody knows. I don't either.