For high ticket items with payment plans, there needs to be a payment plan option.

When someone signs a contract it should show their payment schedule. Otherwise, it nullifies the contract of the terms are different.

Payment schedule should show the down payment, recurring payments, and also allow you to automate the payment based on an appointment date. For example, half payment deposit, half due 1 week before appointment. Or 25% deposit and monthly payments spread out until 60 days before appointment. Flexible payment terms will give users a huge competitive edge.

More importantly, the payment terms need to be in the contract. This is VERY important.