I think it would be possibly the most revolutionary feature you have
added yet, for web designers in quote tools, if you created an Instant
User clicks get started
User selects the type of product/service they want a quote for (like web design)
User selects addons and upgrades (like event calendar, blog section, slideshow, number of pages, theme, etc.)
User see ajax instant updates to Pricing/cart, including itemized list,
full price, and payment schedule (example Initial deposit 50%, Final
payment 50%, total price)
User then continues to Checkout to pay initial deposit (like 50%).
User then has a balance pending due of remaining 50% that has no due
date that can be converted by an admin to an active invoice for the
balance once the project is completed.
This would possibly be done with standard ordering, but needs a few
additional features in whmcs. The forum is littered with people asking
for partial payment on orders and I think this would satisfy several
requests. Products would need an added setting called payment schedule
that allows 2+ payments, so you could pick how many payments, set a
title for each payment (ie deposit, 2nd phase, final payment), and set a
percentage or set fee for each. On the payment schedule, if each are
set as percentage, it would have to add up to 100%, or at least a popup
warning when saving would warn it does not equal 100% for the math
challenged, unless one of the payments is a set deposit and then it asks
for remaining balance on the last payment.
This payment schedule would be applied to the total of all addons and such purchased with the root product.
Maybe at checkout the itemized list could be created as a quote (User
clicks "Let Me Think It Over" button) or could choose to do the initial
deposit (User clicks "Alright! Let's Do It!")