Fundamental questions about financing

I mean, of course you can finance over 5 or 10 years. Rather 10 years, since the difference isn't that big. However, with your good conditions, the problem of "I feel like I'm being cheated" still remains. Not only would you knowingly pay about €35k more, no, the monthly rate resulting from the bank's arbitrariness would also be €200 higher.

A psychological approach: How much additional cost does the higher interest rate cause? Add the amount to the purchase price and consider whether you would pay this price for the land

Very good approach. I would also calculate the difference to the counteroffer over 10 years and the loan amount and see what the land actually costs more.

Is the price of the land otherwise market-appropriate?

Due to the inverse yield curve, a short-term loan is also worthwhile because higher interest rates are expected in the long term.

Is the price of the plot otherwise in line with the market?

Well, what does in line with the market mean.
At least the price is being paid on the market, so yes, it is.
Whether it is excessive to ask for 195€/m² plus broker’s commission, plus real estate transfer tax/notary/land registry = 220€/m² in a village with 5000 inhabitants, everyone has to decide for themselves.
At the moment, apparently everything is being taken, no matter the price.
My parents paid 100€ in that place 20 years ago with a better location.

Well, what does market-appropriate mean.
At least the price is paid on the market, so market-appropriate, yes.
Whether it is excessive to ask for €195/m² plus broker’s commission, plus real estate transfer tax/notary/land registry = €220/m² in a village with 5,000 inhabitants, everyone has to decide for themselves.
Currently, apparently everything is taken, no matter what the price is.
My parents paid €100 in that town 20 years ago in a better location.

Well, 20 years ago. I meant, is the €195 the price to be paid in the surrounding area?

Well, what does market-appropriate mean. At least the price is paid on the market, so yes, market-appropriate. Whether it is excessive to ask for €195/m² plus broker commission, plus property transfer tax/notary/land registry = €220/m² in a village of 5,000 inhabitants, everyone has to decide for themselves. At the moment, apparently everything is taken, regardless of the price. My parents paid €100 in that town 20 years ago.

What was 20 years ago is 20 years ago. My parents also bought a semi-detached house from the developer 17 years ago with 320m² of land for €178k.

It also depends on where your village is located; if you are in the catchment area around a big city, €195 without the other nonsense is okay too. We also bought a plot of land in a village with 6,000 inhabitants (30 km from Nuremberg — driving time 25-30 minutes) and paid €150/m² from the municipality almost 1 1/2 years ago. If none of that applies, the next sentence is valid...

Whether you are now willing to let yourself be "taken for a ride" threefold (interest surcharge, purchase price, commissions) you have to decide yourself now.

The bank has clearly stated: "Take it or leave it."

It also depends on where your village is located; if you are in the catchment area around a major city, €195 without the rest of the nonsense is also okay.

We live in the extended commuter belt of Hamburg. By car, it takes about 45 minutes to get to the city, if there is no traffic jam.