How expensive is Tachyon to build?

The title says it all, really. With Maze of the Master out I’d be highly tempted to build a Tachyon deck, especially since I did pull a Seventh Tachyon from the box I bought, but I’m kinda curious how expensive it’s going to be. If I recall, I think there are three secrets you need? Are they all as expensive as Seventh Tachyon?