Can you give me some step-by-step instructions for this math problem: A jewelry store is restocking its shelves. The necklace stand, which can hold 12 necklaces, currently holds 5 necklaces. The ring display, which can hold 30 rings, currently holds 18 rings. The bracelet display, which can hold 15 bracelets, currently holds 8 bracelets. The store’s supplier charges $4 per necklace, $10 per ring, and $5 per bracelet. How much, in dollars, will the store need to pay to fill the displays?