i was about to ask the same thing. LOL
in my personal opinion, you shouldn't waste your money on salvia of any strength. use it to buy some good stuff. everyone has different experiences and i am only sharing mine, not trying to speak for anyone else. this is nothing to be proud of, but i have tried ALMOST everything that can give you a buzz, including salvia and i can say without question that salvia was the worst buzz/experience/trip i've ever had. there can be a big variation with what experiences different people have based on the strength of the salvia and the smoking method. allegedly, smoking out of a bong is the best method, so of course that's what i did!!
maybe there are different strengths now, but i had the strongest available at that time and it was nowhere near 120x...i don't think. if there is 120x available, i can't imagine what kind of things might happen to your head. i don't think i could tell all of the details even if i wanted to, but i'll spare you guys.......i think all i need to say is that for about 30 minutes i believed with all of my heart i was a bound novel in a bookcase with other books, as well as my friend who was with me, and i couldn't understand why they couldn't "move over" so i could add another f-ing chapter!!!!
i should add that during almost all of these 30 minutes i was completely blind or either i couldn't physically open my eyes and i can't tell you which one with any confidence. i lean toward me not being able to open my eyes since salvia seems to have a paralyzing effect that can hit you like a ton of bricks w/in 5 secs and this applies to your entire body. once it wore off, there were no lingering effects (thank god) except for the complete disbelief at what you just felt.
my only serious advice to anyone who may be trying salvia for the first time would be to start out with a very small amount. you can always add more if you need to, but its impossible to give it back once you realize that you may not be the badass you thought you were (see my story above). i completely understand how it is with trying new stuff, so i'm not trying to discourage anyone, just trying to say that you need to understand what you are dealing with (the same with anything else). we were on vacation and ended up throwing away some that we had left before we had to get on the plane and didn't even care. i smoked it several more times, in lesser quantities, during that trip and just never really enjoyed it. personally, i'd rather have some good nugs over salvia any day. good luck