I had this happen more times than I want to count. Now I just have them come to my place. We live in a ~120 year old wool mill converted to lofts, so there are roughly 200 units in the building. I don't give them a unit number, just building number, meet them in the recreation room, and what's done is done. I also only take/answer texts via google voice. If we agree on something I take the time to actually talk to the guy.
I like those new old mills converted to condo places.
Some of them get upgraded to the max with high tech stuff.
Definitely nice and secure if you just meet them at the lobby and don't bring them anywhere near your unit.