No guarantees on used elec parts. Buy one from a reputable seller, and maybe one that allows returns.

Plug in the specific part number from your module into Realoem.com. If you don't see a part number plug in your car's VIN at Realoem and pull up the part. You will likely see some other part numbers that say "Exchangeable retrospectively" In theory, a replacement part with one of these other part numbers will also work, although it is best to find the same part # you have. There are also differences in the avail button on the face of the module. Make sure the unit you're buying has the same functions.

It is unclear to me whether you will need to code the climate control module (IHKA) to your specific car using NCS expert or other coding software. I think you may have to. Please search yourself on this.