Well, (is't that a good word to start with). You've got a problem there. that is, you can't usaly find just the script you need. There's always that little thing that has to be modified... So i recomend you to find a good tutorial abut it.
But if you really want such a script, and you want it now, i can mail you the one i'm working on. It's a money script that feutures (nice spelling eh') the following:
1. A number of gunrunners to trade weapons with. They can be placed anywhere on the map, and even set to move around.
2. Each gunrunner will have a list of the weapons he currently have, you can buy and sell weapons of the list.
3. Each (let's say) five minutes, the lists will be shuffeld so the game will get new weapons (and loose old) all the time. Of course, that time can be modified. Or removed...
4. When the list shuffeles, the prises will also be changed. that way you can make money by buying arms cheep in one town, driveing to the next, and selling them...
5. The script uses the action menu as input, and the hint box as output.
That's about it...
It' actualy almost done... Just need some prises regulated
Let me know if your interestet.
Here's a pic: