While browsing Mouser site for modem controllers I came across this item that seemed very cheap at £0.299 each. Being a good citizen I clicked the 'See an Error' button and reported the price seemed to be moved 2 decimal places to the right from where I would expect it to be. I got in reply a quote confirming the £0.299 price.so can only assume the price is right.
Alas it's not quite what I'm looking for but for eBay sellers I would think there is a profit to be made here.
Dial up modem?
http://www.mouser.com/ds/2/280/86002071-2378.pdf
Old-school.
For $0.50, I might have to pick up a few of those. I finally got started designing a 4xRS232 to Ethernet adapter I've had planned for a while. Dial-up support would be a nice touch, especially if it's already an approved module.
It looks like this is perhaps a "label" containing regulatory approvals and such, that you would stick on the outside of your product if it happened to contain one of their (much more expensive) modules. Other vendors have more accurate descriptions.
westfw:
It looks like this is perhaps a "label" containing regulatory approvals and such, that you would stick on the outside of your product if it happened to contain one of their (much more expensive) modules. Other vendors have more accurate descriptions.
Well spotted, I had looked and looked at this and never clocked the label bit before. I knew it was to good to be true 
Oh. Searching the manufacturer's part number, it looks like you're right.
Then how come Mouser included specs?? This label is operated at 3.3v, consuming 380mW, and is good up to 56Kbps? grrr