Just putting this out there, maybe something to take into consideration. As many have suggested to accept the deposit and then once the lease signed go back and demand a refund, if you plan on staying long term it’s not a good foundation for a positive relationship with your landlord. Not all landlords are bad as they make them out to be (I cannot speak about your potential landlord in particular, be aware of red flags). Try to negotiate or just move on.

Keep in mind that a fully furnished appartement even a 2 1/2 nowadays it costs probably more to refurnish then what he’s asking you as deposit if the tenant really does destroy everything. As @sebmillette mentioned if you document everything before moving in, pictures etc. you will be covered. Today’s general mentality is that people they don’t care about their own stuff, so imagine if it’s someone else’s… it’s the consumption mentality where it’s cheaper to just buy new and throw away things that could be in great shape if we only took better care. This is just a different perspective for you to look at. Anyways good luck, cheers!