How do I make a move?

Just randomly drop a line and say something like "yeah we should hang out or something" and see how he reacts. If everything clicks, you'll be boom blicky bam.

Well, if this is been going for a long time, and he hasn't make a move, most likely he thinks you're there for the free/cheap coffee! Duh! And you're right----if he wasn't interested he wouldn't hook you up with the cheap or free coffee because if he did that to every girl that showed up there, then he would have been fired by now.

Anyway, given that he is not the 'aggressive' type, it seems your only option is for you to make a move. You don't mention in the post if in your chats with him, you have hinted at all if you gave him any type of hints that you're available, or if he even made any hints of asking you out.
Given all the free coffee and discounts he has given you, next time you go see him, do your chat, but this time find out when is his next day off or when is he free; you do that by asking. 'so you work all the times, when is ur next day off? " Once you have that info, then you say: 'since you don't like my tips, and since you have saved me so much money (or whatever you want to say here like 'you have been nice to me etc), I decided I'm taking you out to (fill in the blank) on (your day off); so what time worst best for you? " Now notice, you're not asking him 'hey, do you want to go out? ' You're telling him YOU ARE taking him out and you just want to know what time is best for him.

If you use the excuse that is because of the free coffee/discounts he gives you, then it should make it easier to tell him these lines because you're rationalizing that you're taking him out because of the free coffee; once you take him out, then you better do a better job at flirting! :)

Do you have his number? Tell him you like talking to him and that you guys should go out sometime. If you're nervous then fake your confidence. Just smile and ask him out. Good luck!