Yes, I have given all sorts of diapers and AB related stuff to in-person friends. Even before I knew about ABDL when people at university asked to borrow disposables I would give them some. Then later when I did start to accept AB as a coping strategy it was in-person friends who provided my first pacifier and Onesies.
The first and - as for now - only time I've met up with another DL, I brought him some diapers to try out since I knew he wasn't comfortable ordering online and therefore didn't have access to the "good" brands. There were a couple of abriforms, a couple of abri-let maxi boosters, some Kendalls I don't wear because they don't fit me well, and a jar of barrier cream just to incourage him towards a heavier diaper usage.
I didn't specifically buy them for him, since I have a quite large stock and simply took some from there, but judging from his delight he must have been in heaven. He was even lucky enough to have the Kendalls perfectly fit him, as he told me later.
No wonder he can't wait to meet up again with me...
(he's not taking advantage of the situation, in fact he offered me to pay for the diapers, it's just that I find it so inconvenient to talk about money with a friend, and during a DL-ecstacy moment, and so I declined the offer.)
I've never bought diapers for/gifted diapers to anyone, but I'm about to receive some diapers from a friend who had extras. They're coming tomorrow and I'm excited. In the future if the opportunity arose I would be inclined to share to help another DL out.
I have never bought others any diapers, but I have gotten a cloth diaper for xmas from a very good dl friend of mine. He made it himself and it's awesome ^^. He also got me a paci and a bambino diaper to try.
The only other DL that I ever met up with I did buy some diapers. I knew he wasn't really able to get any, so I got a bag of depends for us to use, and I gave him half the bag when we left. Both other times we met up, we did exchange some diapers. One time he had some attends that he let me use, and another time I had some abena x-plus, and he never tried them so I let him try them. That's pretty much it.