Potty train to save

My son would be almost 3 but he is not yet fully potty trained. He is doing so well in peeing in the toilet all by himself now but not with his pooping. For some reason, he still won't be able to tell if he is about to poop. We already tried our best to have him tell us when is about to go so that he can sit on his potty seat like a big boy. We also set a motivation for him such as his potty seat's color/design which he chose himself and the thought of him being a big boy. I also explained to him the food process in our body and the reason why we poop, as what I've read in an article online. Maybe, it would just come in time, right?

Anyway, it would be nice to have my son fully potty trained so that he can graduate from disposable diapers and we can save money from it. We usually spends about $30 a month for his nappies which means that if he doesn't use it anymore, we would be saving $360 a year. With the economy nowadays, that's considered a big savings. But I know, saving money is one thing and it's not the most important. The most important is his development as a child.

I can't wait to see him poop all by himself in the comfort room just like how he pees all alone.