I have found that design companies tend to keep the price the same if they work with you and feel a long term easy going relationship can result.

It's is usually when i don't have clear defined gaols as to the design and in turn they don't have clear defined goals that creates a problem.

Usually when they raise there prices it means they are tryning to be nice and say plaese don't come back. (:

It's not uncoomon to work with a design company and if all goes smoothly have them contact you a month later and offer their services at a lower price just to get you back.

Something must have gone wrong.