Hey guys - here's the lowdown.

The SX65-M is a new model. It's an improvement on our past design. A coaxial style speaker will work just fine in a boat and many many boats out there have coaxial style speakers. The SX65-C is just that. They handle lots of power are very musical and are a good all around speaker. that match the cosmetics and acoustics of our other offerings. The M version that launched a month or so back, departs from the coaxial design and seals the mid bass. In doing the we use the same 25mm tweeter but its mounted into the grille. End result? improved mid bass response.

We didn't change the price. It remains 180/pair.
I would be surprised if any retailer is selling them at 50/pair. That would be far below Exile's MAP pricing.

-Brian
Exile Audio