That could be due to several possible legitimate reasons in addition to the obvious. The key fee may have been set 20 years ago when 10 dollars was reasonable and not updated to cover labor and the deterrent effect for losing keys. When updating the new system, the cost could have been adjusted to keep up with the times. The new system could be genuinely more expensive to buy keys for (assuming like RFID) or require a more technical user to perform the update. Unlike metal keys that can be pre-cut often manual intervention is required to replace a dead key since there is a database association with the key that needs to be established. $50 is enough to be a deterrent and not enough to be considered excessive considering that replacing a car key can run over $200 for the fob alone depending on make and model.

I recently reverse-engineered the keyfob for my building because the official one is big, ugly and expensive to replace (after I've already paid fees to replace 2 lost ones).

The result was that 1) the system is absolutely insecure and can be cloned very easily and 2) all the hardware I needed to reverse-engineer & copy it (including several new key fobs) cost me the same amount as a single official replacement.

I don't think the building owners are setting the price either, it's the vendor of the "security" system that is reselling cheap insecure crap at 20x the real price and exploiting information asymmetry to sell them.

At least with low-tech solutions like old-style keys everyone is on a level-playing field and selling them for 20x the price wouldn't fly (because it is common knowledge that a locksmith can make you a copy for the price of 2 cups of coffee), but this kind of new tech allows them to get away with it, and this trend will only get worse as "landlord tech" advances.

Regarding car keys, the astronomic price you mention is also price gouging just because they can. The actual hardware is not expensive at all, it's just that they (officially) need to be programmed by the dealership and that allows them to set any price they want. Of course, there is software and tools out there (if you look in the right place) that will completely defeat the apparent "security" provided by such system so you're not even gaining anything regarding security.

I knew a facilities director who found out when people changed staff at one of the facilities he managed they wound up getting swindled by this crazy contract the locksmiths had the organization signed up with. The problem was keys were being copied and proliferated and accountability of who accessed which rooms and buildings in the complex was no longer manageable. The solved that problem but took an a host of other costs with key replacements and who owned the master key set. From what I remember the locksmith company owned the masters and charged a crazy amount for key copies. I forget the details exactly but I remember the sentiment of the director being that the contract was heavily biased in favor of the locksmith company.

Well I didn’t sign my original lease for that building 20 years before the switch so if the traditional re-keying process had become more expensive I assume they would have simply updated their lease terms.

Your list of vaguely plausible what-if scenarios is exactly what I’m talking about. Neither of us has any idea what the true costs are, but for some reason the tech makes us more open to accepting what is at the end of the day an erosion of tenant rights and services.