Ted's Machine shop in lower-Kalihi off Nimitz has Torco. I buy 3 cans at a time for $28 ea. Not too bad considering shipping this stuff is expensive to Hawaii. I'm trying to talk them into carrying Boostane as some have said it is a tad better than Torco, but they are a Torco dealer, so that's what they'll carry.
I don't use it every fill up, just mainly for weekend fun with a tank or two of straight pump gas in between. I can tell you it works, as I do my own tuning, and I definitely get away with several full degrees of timing before onset of any knock (Dyn Advance negative timing) compared to our 92 octane pump gas. The timing I can get with the a/f ratios I target are pretty close to what I can get on legit 100 octane unleaded race gas, and that is going with 32oz for every 10-12 gal (true in-tank amount accounting for the approx. 2 gal of reserve). Make sure you are running a tune for the increased as gains will be minimal to nil with stock tune.
Just understand that Torco leaves an orange coating on your exhaust parts including turbines, and although it's safe for use with our O2 sensors, it will ultimately somewhat shorten the useful life of your spark plugs compared to straight pump gas or E85. No a bad tradeoff, but if we had E85, that is what I'd run, but no soup for us in Hawaii.
Going on the dyno this Saturday to see what I'm getting on my basic FBO (still stock cutback and intercooler) set will do.