It’s not too late to bid on the new, sealed-in-box 16GB iPad being offered by egiftscentral_123 — an eBay “top-rated seller” with 99.3% positive feedback — for the Buy It Now price of $21 million (plus $14.42 for shipping).

If that seems like a lot to pay for a tablet computer you can pick up at your nearest Apple Store come April 3 for $499, that’s probably because you haven’t checked out the other iPad offerings on eBay (EBAY).

On Sunday morning, two days after Apple (AAPL) began taking orders online — and three weeks before the device ships — a search for “iPad” on eBay turned up 2,078 listings, from iPad screen protectors to iPad-ready purses.

The big money, it would seem, is in iPad domain names — Web addresses that will presumably generate a lot of traffic if the device takes off. We counted 312 offerings, many for multiple sites. At least five have a Buy It Now sticker price of $21 million, including ipadsurfs.com and ipadinternetstore.com. There were no takers Sunday for stealtheipad.com ($1 million), ipad-hacks.ca ($3,000) or ghettoipads.com ($1,300). But internetipads.com had at least one bid — $10 from a veteran domain-name trader list as _***b.

The hottest action Sunday was in auctions for the iPad itself, 394 in all. The 16GB Wi-Fi iPad was the most popular item, followed closely by the 64GB model. Serious bidding seemed to center on offers to ship iPads internationally on April 3. There were 22 bids, for example, for a 64GB Wi-Fi-only iPad that shipped oversees for a flat $59 rate, a $699 value (not counting shipping) with a top bid of $860.

A 23% mark-up might make sense for a buyer who really wants an iPad and lives outside the 10 countries where the devices go on sale next month.

But as always on eBay, it’s buyer beware — especially when the bidding goes into eight figures.

See also:

• Day 1 estimate: 120,000 iPads sold
• Apple sells 50,000 iPads in two hours
• The wild iPad Ruckus begins
• How many iPads will Apple sell?

[Follow Philip Elmer-DeWitt on Twitter @philiped]