Apple give very low margins to retailers and they've been consistently low priced compared with the competition hence the dearth of other options. You can probably find RIM Playbooks for a good discount as they're overpriced and not selling.
For a laugh look at the details coming out on the new "ultrabooks" to compete with Apple's Macbook Air (US$999), they're at US$2,000 already.
Ultrabooks to start arriving in September, more expensive than expected -- Engadget