Deadshot

Update: I got the money but, when trying to pay with card I get this message. I tried this morning and tried later on and I still get the message

Oh ok, thanks for the info!

So I'm thinking of buying a custom class, so I checked out the custom class info and you have to pay $5 but each gun costs $10. Am I able to buy the guns later after I buy the initial custom class for $5?