Before comparing anything, can you confirm whether “fixed for 30 years” means the rate is contractually fixed for the full tenure? That wording would be the first thing I’d verify in the formal offer. Also, how long do you expect to own the property, and are the arrangement fees paid in cash or...
That three-way choice is sensible, but I would test it only on new Berlin property threads first. Put it in a compact mobile section and leave old threads alone initially; migrating them would create work and uncertain entries. If members actually use the resulting filter, older high-traffic...
There’s still a seasonal possibility, but it needs testing rather than repeating what agents say. Did similar listings appear and disappear in the same period, or is the slow stock concentrated among homes with obvious compromises? The second pattern would weaken the seasonality explanation.