Time awards are an interesting idea. I don't think you could have both in place at the same time. It's difficult to race for time/place simultaneously. Guys are not going to want to share the pace if it hurts them in place. Also, a time bonus would be impossible for a meet director to budget. If the bonus was for sub 12:50, 1 guy or 5 guys could go under. For place, it is easy since there is only 1 position per place.
If you're talking about Bolt-type stars the problem is their endorsement income dwarfs their track income so greater track payments will not entice them to race more often.
The problem with track is unlike other international individual sports like tennis, there is no agreed-upon format for competition between meet promoters and athletes.