Ships can easily be made cost free using an app I created called PartArt: Space
It lets you place the ship parts created by Skorpio in a semi-symmetrical manner: Moving them up, down, outward, inward, rotating left and right, and scaling width or height. You can cycle through each piece after it has been placed, delete parts, and change the Z order of the parts. I find it easier than GIMP etc. You can use asdwqe keys to do some of the movements.
Flash: http://www.astroarmada.com/partart/
iOS: https://itunes.apple.com/us/app/part-art-space/id687600025?mt=8
Any thoughts? I hope to take it a step further and allow importing sprites from urls, saving layouts to MySQL, and possibly adding it to the space game I keep recreating so users could custom make their ships.