Not going to argue the safety issue. Also not sure about overall costs. But I can tell you that, in my experience, motorcycles hold their value very well.
I bought a Ninja 250 a few years ago. I traded it in when I upgraded to a larger bike, and actually got more money for the trade in than what I paid (thank god for desperate people on craigslist). Maintenance costs weren't huge. One carb cleaning, a new tire, and an oil change were about $350 total for two seasons of driving. Fun little bike btw, and I got around 60mpg, and trust me I kept that thing revved up pretty high.
The bike I upgraded to, a Ninja 650, was such a blast to ride. Again, I didn't experience any large maintenance costs. Fuel injected so no issues with carbs, tires kept their tread for the 4k+ miles I rode the bike, and one oil change was like $20. I got about 45mpg, so a lot less than the Ninja 250, but also more than twice what I get with the cage.
I ended up selling the 650 to someone on craigslist. I did "lose" $400 on the sale from what I paid at the dealership, but overall I don't think losing 10% of the value of the bike over two years was too bad, especially since I bought it from a dealer and sold it privately. I knew I wasn't going to come out ahead on that one. And selling this bike allowed me to pay off my credit cards, so I'm happy.
One day I will ride again, and it will be glorious. Hopefully by then I will be living somewhere where the riding season is longer than 4 months. I do feel that maintenance on a motorcycle is a lot easier than on a car, and if you do it yourself you are going to save a lot of money. And the mpg is so much better on a bike compared to a car, unless you own a ZX14 or the equivalent.