That is not a typical symptom for a bad starter motor. It sounds more like the power deliver to the starter may be varying as you continue to push the starter button, making me suspect the relay.
I see that you have an '05 but you did not give us too many more details to go on, like how many miles you have on it, and whether the problem is worst with a cold bike or perhaps it's worse only when hot (which would be more in line with a bad starter motor).
Try measuring the voltage at the starter motor, if you can, or at the starter side of the starter relay. I suspect that the relay contacts may be degrading and inhibiting current / voltage delivery from the battery to the starter. Another good test is to measure the actual voltage being dropped across the relay while cranking. It should be minimal, and not vary much from one stab of the button to the next.
The problem with measuring the voltage at the battery while cranking and watching for it to dip is that it provides a chicken vs egg dilemma. Is the battery voltage sacking out due to a bad starter motor, or is the (new) battery just not up to providing the required cranking amps. You would not be the first person to have bought and installed a bad battery. You would need to measure the cranking current to differentiate that.
Out of curiosity, what brand and model new battery did you install?