Lauren's right.
You're best bet is to find a local friend you can trust, who gets a steady, consistently good flow of it.
The best way to do it is find a dealer/chemist at a show, be his friend and then make trips out and buy it there. But its always a gamble, there's no way (short of running extensive lab tests) to find out how potent the LSD is. The best way to gauge it is to talk to people who have dropped from whatever batch is currently floating around, that way you'll know prices and potency so you can figure out how many tabs will get you how far.
Acid is not this murder your spinal fluid drug at all. It's just not like that. There's alot of urban legends concerning the effects. But then again the truth is, because of the Owsley laws, synthesizing pure LSD is hard to do. Since chemical purchases are policed by the government any suspicious purchases will be checked up on, the same goes for cocaine or herion. And those who do make it pure, well it takes a while to earn their trust most of the time.
Further - since its hard to exactly replicate lysergic diethylamide many people take shortcuts. So in order to gauge OD/LD-50 levels (LD-50 levels, while damn near non-existant, are there, but you'd need to ingest thousands of grams to kill yourself, and by then it will your actions, not the effects of the drug that will kill you), effects, etc is hard to do due to the multiplicity of types.
As far as the acid and shrooms comparison goes... tough call. There are a fleet of mushrooms that contain psilocybin, again making it hard to compare the two. Plus growing conditions, bacteria, etc. And then your own body chemistry, current state of mind/body, its damn near impossible to come up with an accurate comparison.
-AndrewP
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Per solitudinem ardere in remedium formidinis dictitabat.
'It is often said that the best remedy for fear is to burn alone.'