Hide shipments for other classes that can't purchase? DarkRP

[KrystalBudz]

Hello,

Right now in my server, gun dealers are the only class that can [I]buy[/I] guns in the F4 menu, but currently, all other classes can see the guns, but when they try to buy them, it says /buy has been disabled. I want to know how I can disable other classes from seeing shipments that they can't purchase. This is probably something simple I missed, but I can't figure it out. And yes, I have googled til I couldn't google anymore, looked in a bunch of files, all to no avail. If anyone has an answer, it would be much appreciated.

Thanks.