200K real estate purchase with 80% equity (unexpected inflow)

And then the interest rates are much higher, because you can only get a consumer loan?

Irrelevant to your question, because the notary does not care.

And then the interest rates are much higher, since you only get a consumer loan?

yes, that is usually the case

And then the interest rates are much higher because you can only get a consumer loan?

They are not the problem - over the term of the financing you might even pay less interest (48 months vs. 10 years or more). The much bigger problem for many is the period in which the loan must be repaid. Maybe it's 72 months, so almost 600€ repayment.
That is why a consumer loan almost never works when it comes to needing full financing because you have no equity (and also no good credit rating for full financing) and think you can finance the incidental costs of the purchase through such a consumer loan.

Let the loan run and invest the equity in the next project.