While it does have a once per turn limiter, that wont stop you from getting insane value
Most versions of the legendary in Red and White are $10 and under, except for two variants
It gets a little better as well if you're running a Lifegain subtheme, perhaps with Heliod, Sun-Crowned in the 99
When you can play it the Cloud brings awesome power offering a pretty good representation of a Mind Twist, an Armageddon, a Wrath of God or a Fireball, often a couple of those things and almost always far worse for your opponent than you
There's a lot of Equipment that can be attached to Helitrooper for free after that cost reduction, both in Limit Break and in Magic at-large
At twice the mana investment of Faerie Mastermind, thats right on rate for what it should be drawing