I think that YES, it is! But it depends on how much you like the theme park games! It's subjective.
I think that Frontier has no interest in attracting too many people in playing the alpha. If I were them, I would have set the same price or higher, because the alpha community needs to be interactive and passionate to the game because the aim is to give feedback, not to play it without helping the devs. Alpha phase is incredibly important for the development. The community of an alpha must be involved. How can Frontier be sure to have a reactive community? Simple: setting a price that only the passionate gamer would pay.
Frontier = quality, not quantity.