And by your math, he would still lose money.
Indeed you are correct, but you are only looking at monetary gain. My point wasn't really about making money, it is that he could get
something in return for his work.
That
something might be $255 dollars, or it might be the time he enjoys learning the SDK and writing the app. He said he wrote an application for the Treo, so apparently the OP has coded in the past.
My original statement only pointed at the bare minimum amount he could if income gained from sale were his motivation. I forgot to take out Apple's cut. There are many hobbyists and tinkerers writing apps for the app store, which is better for everyone. Some might strike out, but many will come up with great ideas. Also, how much time he spends supporting an app can be zero or more hours.
You keep talking people out of writing apps, I'll keep talking them into it.
There IS virtually unlimited space in the App Store contrary to what some believe. The application in the store are not stored on some mystical "shelf" that is running out of space.
EDIT:
By not supporting it, and putting it in the store for $0.99 cents he still makes more than he would have made if he keeps it private, which is what I was getting at in the first place. If there is a spreadsheet app that can do this, then yes, that would make the most sense, unless he just wants to write the app. Which I encourage.