Many domain sellers now offer financing. Usually the terms are very easy and require no credit check, the reason is that the domain remains in the control of the seller or an escrow until the final payment is made. However, even though it is not fully in the buyers control, the buyer can start using the name right away,
A mistake many make that ends up costing them a lot of money is they do not use a reliable third party to manage the escrow.
For example, If you buy a name from John and you made an agreement to make payments and he controls the name until the final payment, what happens if John vanishes? What happens if John stops renewing the name? Sure, you could stop making payments, however, what if you already investment in building the site and brand? What if you have customers going to the site already?
The only way to finance a domain is by using a third party like Escrow.com, Dan.com and maybe one or two others, the majority of domain escrow companies are scams or not reliable. Many times buyers think they are saving some money by dealing direct with a seller or by going to a lesser known domain escrow company, but it usually ends in serious financial loss.
To review a small list of premium domains that sold and their final price click here.