> but if you want to actually sell your products, you still have to go through the process of RF certification (although at a lower cost. Only you can decide if the higher upfront cost of using a module vs. spinning your own is offset by the lower certification cost)

I doubt it was your intention given the disclaimer there, but based on my own research into this issue, this is a highly misleading statement, especially for small volume products.

Full FCC RF certification is not only very expensive, but also very complex from what I understand. It is NOT an easy process. That is why these modules are so popular in many actual commercial products.

If you need FCC certification for your product and use a pre-certified module (and presuming no other radio hardware is present), you only have to undergo the testing for an unintentional radiator I believe, which is a much simpler prospect.

The difference in cost is said to be in the neighborhood of $5K to $10K, though I haven't gotten any actual quotes yet, so I can't give anything definitive there.

Disclaimer: IANAL of any description, and I have not yet gone through this process myself; I'm just researching it as I get ready to produce a product. Do your own research, or better yet, hire someone who truly knows this stuff!