They are quite similar, and even have similar common names, but both are found on different islands, so distinguishing the populations. also, I've heard that inexpectata retains it colour somewhat better, while, as it grows, ornata somwhat loses its colour.
I've heard of inexpectata going for VERY high prices in the states, but im not quite sure what the range is.
Warning: these geckos are VERY flittish, and if you want a gecko to watch, which is beautiful, do not go for these.
regards,
*the moof*