Like anyone, I get lots of spam. Having kept the same e-mail address since 1995 and having that e-mail address posted all over the web may contribute to absolutely inordinate amount of spam I receive. I get over 1000 pieces of spam mail a day.
To make matters worse, I run my own mail server on a Soekris 4801 at home. I use postfix running on FreeBSD 6.2 with SpamAssassin to identify spam. My spam situation is desperate, so anything that looks remotely like spam gets immediately sent to the bit bucket. Still, over 50 spam mail a day make it to my Inbox.
My Soekris box is my mail server, file server, firewall, and PPPoE tunnel end-point (for my DSL connection). I also run a low-traffic web site off the box. That said, between pppd, the postfix and spamd processes, receiving and processing spam consumes almost 100% of the CPU all day, every day. My load average rarely dips below 1.0 and, at the heaviest times, the inbound mail queue grows to a few hundred messages.
Now, this isn't the fastest machine in the world. But when I started my first ISP back in 1995, we ran dozens of web sites (admittedly, mostly static content) off a single 100Mhz Pentium server with 128MB of RAM. Our entire 27000+ newgroup Usenet feed was hosted on another 100MHz Pentium server, also with 128MB of RAM. But in 2007, I'm here to tell you that it takes a 266Mhz Pentium-class machine (with the same 128MB of RAM) running 24/7 just to deliver mail for two e-mail accounts.
So I can tell you personally that the price of spam in 2007 is roughly one Soekris 4801 plus disk space. It may not seem like much in comparison to today's top-of-the-line computers, but it is enough to make me sick just thinking about.