Considering gold is priced at approximately $1,740 per ounce, I am not so sure that the naysayers, except those who urge caution, have a good case against doing this. Even as "collectors" items at $25, if it takes 32 of them to get an ounce of gold, you would make more doing this since 32 * 25 = $800. Seems like a potentially worthwhile choice to "go for the gold" instead when your return would likely be over 2x their value as CPUs assuming you don't blow yourself up.
Then again, since most of these chemicals are likely classified as hazardous materials, good luck to the average home user getting them from a "reputable" chemical supply house because such chemical suppliers will not ship these chemicals to anything other than an address in an "industrial" zone.
9/11 has put a big bullet hole in the garage hobbyist's ability to pursue things like this as paranoia is extremely rampant where chemicals are concerned even though I am sure there are hobbyists out there who pursue legitimate uses of such chemicals and know how to handle them.