Where to find old bottles.

Let me start off with I AM NOT ASKING TO PURCHASE ALCOHOL ON REDDIT.

With that out of the way😅, hi I am an 18yo collector of jägermeister and only jägermeister. But I was really curious if anyone knows a place where I can legally buy/find vintage bottles. Because it doesnt seem to be easy from what I gather. The picture is mine just as a context. And yes ofc my collection is way bigger than 2 bottles.