I wouldn't waste your money on the Helitrox class. Once you finish, you'll wish you had signed up for Trimix. I completed my Trimix course last year and was so glad I chose that one. Regarding these diving decisions, yes these kinds of classes are expensive, but you also have to weigh out how not to waste your money when all is said and done. I think you're also being smart in getting some diving under your belt. I did that too, and the class was much easier with that extra experience. Good Luck!