Yes, we hold the full purchase price on your credit card. While this temporarily reduces your available credit, it is not a charge and will not become due on your credit card bill.
Since your installment plan is not facilitated by a loan, the hold is required to be able to guarantee your purchase to the Merchant. For most plans the authorization will disappear within 30 days of your purchase, but often sooner.
For some plans the authorization will be periodically re-authorized, at lower amounts as you make installment payments, until your plan is complete.
The length of these holds is always determined by your bank or credit card provider, so contact your financial institution directly for questions.
You can find out more about payments and authorizations here.