You might want to consider adding a product to inventory called Down Payment with a price of $1 and a cost of whatever the cost is and another product named Monthly Payment with a similar price and cost. Your users can then add these products to the
Quote and Order as needed. They can leverage the quantity field to get the Price required.
If you want to do something more sophisticated, then you will probably need to consider some customization to the system.
Regards, Donna
       
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