You can purchase a case containing 240 Preemie Swaddlers (good for babies 0-6 pounds) for $60, or a package of 32 Micro Swaddlers (good for babies 1-5 pounds) for $23. UPS Ground shipping is included in the price; overnight and 2nd-day air shipping is available at an additional cost. Business hours are Monday - Friday, 8:00AM - 4:30 PM, Eastern Time.
The Pampers Web site offers some helpful FAQs about preemies and prematurity.
Sources for diapers tiny enough for your preemie.