In my experience, when people show a bottle of liquor to someone they're interacting with, it's not uncommon for that person to offer a shot when they end up cracking it open (I've had friends/roommates/old apt neighbors show me something new they're trying & just offer me some, on more than one occasion). It's not mandatory or anything, but in this context, I suppose I couldn't blame people for being hopeful or expectant to some degree. It's a fine line, I guess. It can get obnoxious, though. Case-by-case situation. Your call, of course.
60 bux is a lot for booze, damn. If I wanted to show people the neat bottle/didn't wanna share, I'd just show 'em after it was gone.