Suggestion 1: I think you should add the ability to limit the amount of something that you can buy from a single sign. This would be cool for things like parkour res's so you could give out a one time prize. This would be really nice. Suggestion 2: You should add the ability to sell multiple items from a single sign. For example you could set up a chest that sells a full set of tools or armour. This would be a popular one (based on how many times Iv been asked how to do this.) Suggestion 3: It would be nice if you added the ability for chestshop signs to send out a redstone signal. You could do something so if someone buys something, you could add a piston pulling out the block under them and dropping them down to the start of a parkour. Suggestion 4: I think that the ability to sell one use to a button would be cool. You could sell a use to a piston or dispenser so people could go on a roller coaster or to get a few different items.
However, someone who knows nothing about redstone would not be able to do this. This would still be very useful to a lot of redstone noobs (me)
Fill your chest with dirt except for one slot for your item, restock the item when you want to give out the prize again.
In regard to suggestion 1: This is possible with a few tp's. At the end of a parkour, have a tp to a room with a tp back to the start. At the first tp, put a redstone wire linked to a dispenser in the room you tp'd to.
Well, it was announced last July or so... So roughly two years Kidding, idk when that wasnt included in the update in what's going on. Only Aikar, Justin, ICC, max, davie, and Shaun know I'm guessing
I have seen something like number 3 before. On smp1 there is a place where you can buy from a chest shop and a door opens. It might have something to do with trapped chests but I am not really sure. After stepping through the door there is a pressure plate that closes it. I am sure this could be done with pistons too. Number 4 could be done in the same-ish way. Maybe checking for the chests signal and the buttons signal.
Just go here for a tutorial: http://empireminecraft.com/threads/buying-use-access-1-5-redstone-edition.23207/