I've had the privilege to partake in many of the 2CX's many times and have found that the thresh hold doses are quite different between most of them. Where one takes 16mgs for a threshold, that same amount of another has you tripping well. As well as the logarithm of doubling of perception is often quite different between RC's. So it goes a long way to say that you need to understand what your getting yourself into.
I've also come to find "from my personal experience, with how I metabolize these RC's" that if you're going to insufflate these RC's you can usually get a relatively equal effect by insufflating about half the dose you would have ingested, Sometimes even more effect for half hit insufflated vs. whole hit ingested.
I would never recommend insufflating these substances without first knowing how you react to taking these substances and how well you metabolize them out of your system.... then again this should go without saying to any cosmonaught, but ignorance does take precidence in most minds when trying to push the bar, usually for the wrong reasons.
Last time I picked up 2CB I was able to score a half gram for $75... mixed hot to 19 fl oz of water with 1 oz of everclear to help disolve and evenly mix I was left with 20 hits rendered to 25mg's a hit at less than $4 a hit. I kept it in my fridge for about 3 months. I would take 50 to 100 mg doses while my girl would take 50 to 75 mg doses. Either way, my point here is even when buying single doses of any of the RC's, I've never paid more than $10 a hit, I'd laugh and not purchase if I was told it cost what the OP said.
I will also advise through personal experience, if you're going to store it this way for personal use (I never sold, always purchased RC's for personal consumption) make sure to measure how many ounces there are in the container before figuring doses, as even in a closed container in the fridge evaporation happens, and can drastically throw off your doses. I learned this after taking a double dose (to me) on accident (nearly 100mgs of 2CI) and wasn't ready for it. Later I measured and nearly half the solution had evaporated making for a veery hot dose (what a trip to say the least). By keeping tabs on what's supposed to be in the bottle, when measuring the solution, it's easy to top off with the proper amount of water/ alcohol solution.
Everything I've said here is in my personal expereince and of my personal opinion, please read the first three paragraphs again as I've stated multipul times these are my educated experiences for my personal self. Ones tolerence is just that... on persons tolerence and caution should be used when figuring out how these chemical compounds react to the individual.
Be responsible and safe, and as always, your mileage may vary.