Early in my entry into reptile keeping, I was keeping a leopard gecko in a large enclosure with a pair of picta geckos.

Surprisingly, given their smaller size, I found the picta (especially the male) were by far the more aggressive - especially around feeding time. I soon had to move them into seperate enclosures, due to the leo getting his tail handed to him (not literally) everytime food was introduced.

Mixing species seems like a cool idea, but its just not worth the risk of injuring your animals. Shell out the $20 for a 10 gal.