How do I know I'm not getting ripped off?

No, you don't, not at all. I started and cycled my 200 with all base sand and rock. I took one spoonful of live sand from my smaller system, and the whole tank cycled in 4 weeks.

 

Ding…ding…ding…ding…ding – somebody give that man a cut-pie doll ! That’s it folks, all there is to it !

 

Food for thought. I have a friend that said they made their own rock out of concrete. Would this work if I put some live rock and sand in with it?

 

takes forever to cure

 

Not in the mix. Just once it is cured, put some in the tank with it. But like supratt said, DIY rock takes forever to cure. I believe the wait time is around 4 months before it can even be safely added to the tank, otherwise you will have serious PH issues.
I would just go base rock. Reefcleaners.org has the best prices, and its free shipping over 30 pounds, which is killer. Then just get a cup of live sand (or small rock, or whatever) out of an existing system to seed yours with. Worse case you'd have to buy one small rock from the LFS.

 

WOW! Awesome! Thanks!;D

 

That Reefcleaners.org is an awesome site and their prices are GREAT!;D

 

*cough*4 weeks*cough*

 

I just bought dry LR (so dead LR) for 50¢ a lb! So I walked away with 80lbs of rock hehe. When I bought cured LR with coralline algae on it, it was $2.80/lb at my other LFS. If anything, just buy a tiny piece of coralline LR to scrape to seed your base/dry rock. Keep ALL your parameters right and it will cycle and cure like you wouldn't believe.

 

When I think of how much I spent on 110 lb of liverock at $6 per pound, I get depressed. If I had it to do over again, I would go the base rock method as mentioned here. Save your money for now, and blow it on corals and fish later.