Pastels can be found for affordable prices, and getting a super pastel fire (superfly) would be a great addition to any collection.

Other genes that could be beneficial and perhaps more readily available for a good price range would be the mojave, or lesser.

You could end up with:

Firefly Mojave http://www.worldofballpythons.com/mo...irefly-mojave/

Firefly Lesser http://www.worldofballpythons.com/mo...irefly-lesser/

Any of these would be a great addition without spending too much!