The sad fact is that a points review (with increases for the good units) rarely reaches the intended goal. You pick units because of their goodness, the points cost is relative, you adjust the list.
If i want to field salamander i will field them, with a less abount of other things. So, points increase won't resolve almost anything. Unless you go to such extreme that you simply don't play that unit anymore (see Nagash price tag).
And no, points increase IS NOT an incentive to play weakest units... on the contrary, if I am going to spend a lot for the top units, I wanna to be sure that the remaining points will go on something valuable.
If Saurus are rarely played, you can just do 2 things:
1 ) improve their rules or
2) reduce heavily their points. Then, people will consider using them instead of skinks.