Is it illegal for a district attorney to offer a defendent a price to buy his way out of a felony conviction.?

Now in detail a da states" you pay 5000 towards restitution before the plea hearing the 2 felonies will be dropped to misdemeanors". Offer is accepted but only 2000 is come up with therefore the da only drops 1 of 2 felonies. Defendant is charged with 1 cl c felony. Isn't that some sort of discrimination if the defendant were wealthy there would be no problem but if they were poor they are sol.