Give me a link please.
Ill copy and paste it to you.
Create a 16x16 baseplate.
Place 3 bricks, and make them red, orange, and blue.
First for the red brick, we're going to make this the brick that will give us a value (the cash)
Do,
OnActivate - Client - VCEModVariable - gold [Add] 50
You're finished with the brick that gives you a value.
Now, let's move on to the orange brick that will tell how much gold we have.
Do,
OnActivate - Client - ChatMessage - [You have <var:cl:gold> gold]
Do that, and click it and it will tell you how many gold you have.
Let's move on to the final brick, the blue brick which will exchange 50 gold for a single gun.
OnActivate - Client - IfVariable - gold [>=] 50
OnVariableTrue - Player - AddItem [Gun]
and click that then you click the orange brick.
So, to wrap it up.
1. Place 16x16 baseplate
2. Place 3 bricks on it.
3. Edit the red brick and click it once.
4. Edit the orange brick and click it once.
5. Edit the blue brick and click it once.
6. Click the orange brick.