Well, I found a very good design for a Redstone shop on youtube back then. You could completely change it (the price up to 5 stacks and the output as well). The user only sees a Redstone lamp and below that a dispenser, where he puts his money in and gets his goods out. If someone knows what I mean or even nice and to search, would help me a lot. I have been searching for 30 minutes.
Kind regards
Ps: It was 2 blocks narrow and about 16 blocks long
Do you mean this one? :