For what it’s worth…
The Beyerdynamic Mce 83 is technically an electret condenser mix, which is slightly different in design than the typical condensers it is being compared to.
This is the reason for several aspects of what has been discussed. It’s why Beyerdynamic can offer such a quality, flat-response mic so inexpensively. It’s also why the output is significantly lower. In the 70s/80s Sony made many similar models and they can sound excellent!
The main issue is the electret design uses a permanently charged backplate which can weaken or degrade over time. These mics typically don’t age well, which is a big reason why they’re seldom made now. So it’s a real roll of the dice when buying used as to how they weee used/stored.
I’ve seen some trustworthy techs refurbishing these models lately - notably Cole Picks Vintage out of Nashville. But be aware going into your future purchases.