Want to save money? Don't buy a motorcycle
First start with yourself. As a motorcyclist, at the very least, you're going to need a helmet, jacket, gloves and boots. Don't think that's necessary? Look at yourself in the mirror. Look at how squishy you are. The fact that you're 80% water means you're essentially a water balloon. We all know what happens to them. Not convinced? Well try this: strip down naked, run as fast as you can down the road, and throw yourself on the ground. Hurts, doesn't it? All that road rash will sting for a few days (or months if it's at motorcycle speed). Figure on spending around $600 for a decent mid-level protective gear set.
As far as the bikes themselves are concerned, motorcycles require replacement maintenance parts far more frequently than cars do. Neglecting maintenance on your motorcycle is like being a professional sky-diver and forgetting to take care of your parachute, or forgetting to feed your 6000 pound pet tiger, who sleeps in your bed.
While a car usually needs new tires every 30-50 thousand miles, most sporting motorcycles will wear out their tires in around six thousand miles, with ten thousand miles as an extreme before the belts are showing. Name brand tires will normally cost you $300 or more installed, or roughly $.05 per mile.
The drive-chain which connects the transmission to the rear wheel, lasts around 15 thousand miles. The sprockets should be changed when the chain is replaced since the sprockets wear with the chain. The cost of a good name-brand chain and equal quality sprockets will be in the neighborhood of $250, or roughly $.017 per mile.
Changing the oil in a motorcycle is important because the oil in most motorcycles lubricates not only the engine, but the transmission and the clutch as well. Because the oil gets smashed up in the transmission and because it collects clutch matter as well as engine debris, changing the oil is done quite often. Two thousand miles is the normal interval for most motorcyclists. This comes at a cost of $50 or so, or roughly $.025 per mile.
The engine on your motorcycle will probably need to have its valves adjusted every 15 thousand miles or so. The average cost is $300 to get it done at the dealer. Hopefully you can do this yourself in an afternoon. If not, you will have to add a cost per mile of $.02.
The total price is $.11 per mile of just absolute basic maintenance. Taking a trip to Miami from Tampa? a 600 mile round trip will cost you $66 in maintenance alone. Fancy a two day, 1000 mile trip to the Grand Canyon? That will cost you $110 in maintenance alone.
Most sporting motorcycles these days are so mind blowingly fast that if you twist the throttle, it'll take your brain a while to catch up to the speed. By the time your brain does, you're already in a completely different zip code. A motorcycle truly is a two wheeled teleportation machine that can achieve MPG in the high 30's, but you will pay for it my friends, one way or another you will.