Can I choose how many items are there left in my inventory?

I don't want to oversell my summer camps, so I'd like to be able to put a limit to the amount of availability I have left for each week of summer camp. I asked this question before, and someone suggest the Gift Registry widget, but I don't think it allows me to add a product option with different pricing and a photo attached to it (like with payments). Any suggestions?

Our payment fields do not have inventory system so the only workaround is to use the gift registry widget or the inventory widget. I'd recommend the inventory widget if you want it to act like products.

Then use the form calculation widget to get the total of each of the product selected by the user. Guide: http://www.jotform.com/help/259-How-to-perform-calculation-in-the-form

After you have the total field, you can pass it to the payment field. Guide: http://www.jotform.com/help/275-How-to-pass-a-calculation-to-a-payment-field

Demo: https://form.jotform.com/80498328480970 (fields are shown for demo purposes but you can hide them especially the sub-products and total)

Feel free to clone this form so you can review the calculation.