I know they've got a zipped pochette which comes in different sizes called "Sénat".
The PM is a LV key pouch-like, in Paris it costs around €300 for classic colors and €400+ for special colors. (yellow, blue, green, white, burgundy...)
But as you can see it's the price of three LV clés... Personally i think it's not worth buying, the quality is not as great as LV and it's more expensive, but if you really like it then go for it.
(sorry if my english is bad, i'm french and 17 so it isn't really easy for me to traduce)