The cool cats at iPodMeister do have strict rules regarding what CDs and DVDs are acceptable, but note that if you bought your CDs in a record store, you're probably good to go. They do require both the original jewel case (remember those?) and the original album artwork, however. If you've got binders full of original CDs, but no inserts, you're out of luck.
So what will the various iterations of the iPad cost you? The full breakdown's past the link below, but you might be surprised -- an iPad ain't cheap.
iPad w/ Wi-Fi 16 GB = 600 CDs or DVDs.
iPad w/ Wi-Fi 32 GB = 700 CDs or DVDs.
iPad w/ Wi-Fi 64 GB = 800 CDs or DVDs.
iPad w/ Wi-Fi + 3G 16GB = 950 CDs or DVDs.
iPad w/ Wi-Fi + 3G 32GB = 1050 CDs or DVDs.
iPad w/ Wi-Fi + 3G 64GB = 1150 CDs or DVDs.
All in all, it doesn't seem like a bad deal – especially if you've tried selling your CDs to a used record store lately. iPodMeister even pays for the shipping costs of the CDs and offers the digitizing them for an extra "cost" of 70 to 250 CDs depending on the amount you've sent them.