My kid is 5, he will collect about 10lbs of candy. At the rate we let him consume candy, there's basically no chance of him finishing it before Christmas, where he'll acquire additional candy. Then his stock will be replenished by Valentine's, then again by Easter. Because my family is Orthodox and my wife's is regular Christian, he'll get two easters (most years). There's a summer lull, but he'll go to several birthdays which will give him goodie bags, which will help keep his candy topped off.
The tax is necessary!