I have seen it quoted many times that the average pc is worth about $5 in scrap metal and PM. Hopefully I am wrong, eh? The best pc scrap is free. From what I have found locally, companies cannot simply throw away old computers and monitors, due to the "hazardous" materials they contain. So, instead of paying a fee, some will stockpile the stuff in a spare office or warehouse. Finding one of these is a scrappers dream, and the only way to make a decent profit.
I recently ran across one of these stockpiles at a company that the place I work for does business with. They had 3 old monitors laying outside on a pallet and I asked what they were going to do with them. I was told that they had a small warehouse (called the admin building) full of pc's and monitors that they have been saving since the 1970's, and they would just be thrown in with them. When I inquired why they did not simply throw it away, they said they had to pay a fee for every pc and monitor they brought to the landfill, so they just pilled it up untill they could find a better solution.
Now I do not intend to deal with e-scrap because of the slow turnaround time, but it was hard to refuse this. I offered to solve all of their problems and haul all the scrap off for them for free. I'm awaiting approval by the higher ups. My point is, with a little luck and probing, you can score huge amounts of e-scrap for free, and even be seen as their saviour for taking all this "junk" off of their hands. Paying 20-30 euros per PC will not yeild you any refing profits from what I understand of the yeilds.