We are going to be using Catholic Charities of Dallas (not sure if they also have a Ft. Worth office or not). Here is the break-down of when costs are due:
$250 - application fee
$1500 due at 1st homestudy interview
$1500 due one week before first seminar
$5000 due within 15 days of notification of completion of home study
remainder of fees: due at placement of child
I haven't asked if they have any sort of payment plan for the "remainder of fees" part in case you don't have all the money you need at that point in time, but you could definitely contact them to ask.
I also wanted to say that you shouldn't be discouraged by the fact that agencies often require larger amounts of money early on in the process. I would guess that few families have this kind of cash in hand when they start out on their adoption journey - I know we didn't (still don't, in fact). We've been saving for about a year and have less than half of the money we need in place. However, we have enough money now to pay all of the fees we will need to be in the pool of waiting families, and we should have the rest saved by the time we are placed with a child.
I guess what I'm trying to say is, don't let the money discourage you too much. You can take some time to scrimp and save until you are comfortable with the amount you have to get started - it may take a few years, but in the meantime you can be educating yourself as much as possible about adoption and all of the issues surrounding the process. GL to you!