ProPins are made in Germany and are a licensed Disney product. However, many people consider them to be much inferior quality (but not as bad as Sedesma) to those sold by Disney.
Since they are licensed and legal, technically they are tradeable with CM lanyards. However it is very unlikely that you will find any trader willing to accept them.
Yes, it will allow you to get better pins off a CM lanyard at a low cost, but it will also give a reputation as a cheapskate.