I wish I had numbers for you. I would be interested in knowing some myself. Guess I'll need to start keeping track of these things.
But to be honest, my 2005 DL650 (38,000 miles) has barely cost me anything significant really. The saying "just oil and gas" just about covers it. I don't ride between November and April, so that just leaves 6 months of actual riding. Every season before I ride I have had the bike thoroughly inspected, oil changed, etc. So far, I haven't had one bit of trouble with it.
This year, I had the Suzuki 7500 mile factory servicing done which ran $500, which is the most I have ever spent. I'm also looking to get some new tires this year, which will run another $500. Next year, I'll have the brakes replaced which will run about $250. I think my insurance runs about $200 for the entire year. Each long ride I put about $11.00 of gas in it and ride for a long time. If I lived in a warmer climate, I would seriously consider ditching one of my cars and just ride to work everyday.