I ran into this situation myself, but the dealer was more than willing for me to pay for the guns, then just time it so I dros every 30 days.
I played it safe and spread it to 40 plus days myself. What I have noticed is I will go through a period where I will make mulitple purchases then lay off for a long time.
The issue for me is staying out of gun shops. I need to put my waist on a diet, not my wallet
Nicki