Thos, I think if I had 2 10D's and a whole lot of glass, I'd part with the bodies and maybe a lense to get into a Mark II for nearly zero cash.
You'd still have 26 ways to get to 400, and 12 ways to get to 50 
Personally, I"ve spent in excess of $6,000 last year, with the 10D, flash, the lenses, the Photoshops, pods, 3 bags, filters, monitor, more RAM, printer, CF cards, etc etc etc. There is also ink and paper which add up, though I haven't added those up. This year, I'm going to be more judicious - another tripod and head, a 2X TC, and then I don't know...
I didn't plan on spending that much, but you get sucked in. If I didn't get the 70-200 2.8 IS restriction slapped on me, I would have mindlessly kept going. That was a win-win in my book, as I had time to sort out what I really needed
For those that weren't around to follow that saga, in exchange for buying the 70-200, I concluded a binding legal agreement with my wife to restrict purchases of bodies and lenses for a year, and a cap on discretionary purchases for a year as well, with a "cooling off" period which just expired.
