I'm like Klein. I don't want to add it up. I try to think of each individual part as value added to what I need, and I try to work the cheapest parts I can, but I know in the end they will add up.
When I built "Jazzy-Ray" for my friend's daughter (link in my sig) I kept track of the cost. He didn't want to know, and I don't blame him, but in the end he spent a total of $1,100. And that didn't include the $5,000 in labor I charged! (ok, seriously he bought my family dinner at Red Lobster as thanks)
But I haven't tracked my own builds. If Jazzy cost $1,100, then the Monster was more than that!