Our sales team use Salesforce to track deals. One of the products that they sell are email sponsorship which are typically sold in finite quanities e.g. 100K recipients or 25K recipients etc. We have 72 different types of emails which are sent over the course of the year, each of which has 300K recipients can be sold.
I'd like something in Salesforce where the salesteam could choose any of the 72 different email and see how much of the 300K has already been sold. If it's less than 300K, they should be able to 'book' some of it, and then the availability for that specific email would be reduced by the amount that was booked. If they try and book more than is available, an error message would come up and they wouldn't be able to book the amount.
Given that we change our email program relatively frequently, we would have to have flexibility to add, change or subtract the emails e.g. 72 might go up to 73, the 300K limit may increase/decrease from time to time etc.
More details can be given if required.