True, you could make more with proportional or proportional & 0% fee.
I doubt Deepbit achieved its current size -- 45% of the entire Bitcoin hashing network -- through sex appeal.
I think the PPS option had something to do with it -- so it's not too ridiculous to use that in calculations. (As an aside -- someone should do a poll: "Are you doing PPS mining?")
Anyhow, I'm trying to update my own thinking on "what's what" for 6/25/11.
I bought a used gamer tower off Craigslist for $350. It had a 5850 in it. It had a $290 CPU in it, 4 GB RAM, as well as a 500 GB hard drive, DVD drive, and a Corsair 650W power supply. They threw in 4 GB of DDR2 DIMMS, which I used in some other machines.
Overall, an awesome deal -- but then I paid $180 for a barebones tower (mobo, Opteron, 2 GB RAM, no PSU, nothing else!) with 2 PCI-E slots that don't like 58XX series Radeons. So I got a horrible deal there. I guess they balance out.
Anyhow, for my purposes (a miner), your deal isn't THAT different from what I got (above). It doesn't have an HD, DVD drive, case, etc. but of course that isn't necessary for mining. Your system wouldn't be a good deal at all for a non-miner.
BUT -- I did that aforementioned deal (the $350 gamer rig) a few weeks ago (at least 2 "difficulty levels" ago). So I've already made back some of the $350. If I bought the same system today, it would take twice as long to pay off.
Now the gamer rig would sell to a gamer easily for $600 if I was patient. BUT the system you offer is clearly just good for miners. You didn't even bump up $5 to a 3.0 GHz Athlon II like I did ($36). Your system is going to have 0 resale value after mining is gone (assuming it will ever be gone) -- except the video cards of course.
It got me thinking -- is it still economically feasible to buy new rigs -- even low-end, barebones, "just what I need for mining" ones? I spent some time yesterday researching video cards online; looking at prices and figuring out ROI. The best cards now (with rebates, free games, etc.) are coming out to 55 days to payoff. And that's with proportional pools
So if it's difficult to buy any new cards at brand new/retail price, how much harder would it be to break even
A) if you had to buy a whole SYSTEM
B) If you're paying eBay "Bitcoin mania" prices for your card
Hopefully the mining situation will look up soon -- I'd like to see that famous chart that shows the Profitability of Mining -- I bet it shows we're at quite a dip right now, especially with the BTC at $15.