I have the chance to buy either:

1) A helicopter cube
2) Mosaic cube
3) Prof. Pyra


How would you prioritize?

I'd go with a Professor Pyraminx. The Helicopter and Mosaic Cubes are relatively easy, but I'd image the Professor Pyraminx being quite hard. Try and get all three of them in the future though.

I havent tried the Mosaic (Fadi) But I reckon the Helicopter is the hardest of those three.

I will say the Prof Pyraminx tho. Its so nice

Actually the HC isn't too difficult at all.

Not necessarily based on difficulty, tho

What about just overall interest?

It all depends on your own personal preference, of course. Personally, I'd get the helicopter cube first, because I love jumbling puzzles and I love the look of the helicopter cube. Then, I would get the fadi cube, because I always liked that puzzle, and I'd pick up a professor pyraminx later.

I cannot vouch for the Fadi Cube or the Professor Pyraminx as far as solving goes, but I can say that the Helicopter Cube is one of my favorite puzzles. The jumbling great to mess with, and solving it is very fun, with or without jumbling moves.
I would say it isn't incredibly diffcult to solve, but it definitely worth every penny you pay for it.

Go for the helicopter cube. I don't own any of these puzzles but it's the one I want most

Better hurry! Stores are running out.

That's the one I got Now, to save up a few bucks here and there for mosaic, then Prof. Pyra!