Saying no to new toys

So recently my sons memory has been really good, and when he finds a toy in the store he wants he keeps asking for it day after day, I’m talking first thing when he wakes up until he goes to bed. I’ve explained to him non stop that we can’t have every toy we want and we can’t just whine and get what we want. But you all know how almost three year olds are, we have to repeat it constantly.

Anyways the point I’m getting to is if there’s a toy that seems really special to them that they want over everything else how do you go about it? Do they have to earn it? I feel like I’d like to give him a chance to do something to earn it but I’m not sure how to go about it because he can’t really do any chores to “earn money”. I did make an attempt to teach him some humility after the non stop whining and I had him go through all of his toys and pick out the ones he no longer likes to put in a box and I’m going to have him give it to another kid, But aside from that I’m really not sure what else to do.

Any have suggestions or things that you have done?