Not enough information to give you useful input.
That is over 25% of your stash. A lot of money for a place you will only use 1/3 of the year.
Well, yes. I would not sell parts of my portfolio but rather just finance it.
What are your FIRE goals? How much are you able to save toward those goals with/without this property?
My initial goal was €600K, but given inflation etc. I have upped that goal to €1M. On my current trajectory I should hit that in the next 2-3 years.
My savings rate is well over 50% and this year could be the first year were my passive income (dividends and interest) could cover my cost of living (more or less).
If I opted to pay it off in 15 years, getting a fixed rate for the first 10, this place would cost me around 1500€ per month.
Assuming that I use it 1/3 of the year, it's empty 1/3 and rented 1/3 at €50/night (net), the cost per month would be closer to 1000€, I guess.
Why this particular property? Are there other options -- either renting or buying -- that would give you similar benefits at a lower cost?
My main reasons for buying over renting are mostly convenience, especially for longer stays.
Sure, I could rent a different AirBNB each time I go, but having ones own place provides a lot more flexibility.
For example, I could have a proper office area (to work remotely), which most tourist rentals lack.
I could also leave a lot of my stuff (clothes) etc down there and would not have to "haul" things each time.
In terms of cost, there are certainly cheaper places available. The "base" cost for something that fits my standard seems to be in the €120K to €150K range, but that's usually quite small, without a balcony, sea view and sometimes requiring remodelling.
This place for €250K comes with a roof-top deck, a seaview and has recently been remodelled.
It also has a good location, being only a few minutes walk from the beach and city center.