That date in 64 regularly sells for $50-$60. Even if the slab says 64+, that's about all I'd pay for it based on the pics.
It is a reasonable price for an attractive coin. I like it! I think it is a wee bit over graded--I probably would have gone MS 64, but the eye appeal is nice.
Their pictures seem a bit off. Their MS64 looks a *heck* of a lot nicer than the one in my original post.
Use the PCGS and NGC guides. PCGS photo grade gives you an idea what they are looking for in each grade http://www.pcgs.com/photograde/