I bellieve Marlin still has some in stock and, as I recall, at a more reasonable price than I had seen elsewhere, including on internet sites. Why not go right to the source, I advise. Call their 800 number.
I bought some about a year ago, but I just don't recall the exact price.
It's a great and very unusual looking gun. I bought one used, and the old magazine was a bit raw and caused some jams, but the new mag is perfect.