The other terms of the sale are not public information, at least in my state. That said, my former MLS required we disclose any seller paid costs (and so does a HUD statement) . It would be rare that a buyer paid additional costs, but it would have needed to be recorded in the MLS after the sale.

One purpose of the MLS was to keep an accurate database of information about sales. It's used by realtors trying to price homes and used by appraisers. This is why that kind of info was disclosed--so people belonging to the MLS had a full and accurate picture of a sale. The information was not available to the general public. It could be disclosed by a member to a non-member looking to buy or sell a house. In general I would have only disclosed this information to a client. I would not have disclosed it to someone that called me up and was just curious.

Here is the DC/MD/VA MLS yes, I can see that there was a "Seller Subsidy" and how much, but it doesn't say what it went for, just the total.

I can also look up the sale amount and if there was a mortgage and how much.

This information varies by state, what state are you in?

condo is in Illinois