I agree that buying a new replacement spindle is, by far, the best and least pain solution in the long run. My opinion about the damaged spindle is that there is no way that only the threaded end is bent -- the whole spindle is bent to some degree because the bearings are simply not stiff enough to prevent the spindle from bowing.
Hopefully, the pulley will remove from the old spindle (if the spindle is warped, there may be a problem). Installing new bearings is no biggie if you know the Do's and Don'ts -- otherwise have a machine shop do it for you. Definitely do not use the old bearings: They are likely damaged and you wouldn't be helping things by removing them from the old crooked spindle and pressing them on the new spindle. I have made my own bearing pullers and presses by using all-thread, nuts, washers, various PVC pipe fittings, and bronze bushings. Also, you can often drop a bearing right onto a spindle without a press if you chill the spindle in a freezer for a couple hours to shrink it. Assembling everything after removing the spindle from the freezer requires working rapidly, installing the bearing in one smooth fluid motion (don't stop at midpoint to admire your progress -- else it may not be anything to admire), and making certain that you don't cock the bearing.
Bill