Potty train as soon as possible!! LOL.
My first child took forever and my second was potty trained before 2.
Buy on sale, use coupons and try different brands. When my kiddos were young, I liked the Target brands and I even purchase the supermarket brand. Each child had a different body type. So older DD was more a Pampers girl and younger was a Huggies girl - or was it the other way around?
Basically one had a rounded bum and the other a teeny one and different diapers fit better and prevented leaks. But I was able to find generic ones that were a lot cheaper that fit well.
When we were potty training, I would take off the diaper and make them sit on the toilet to go every few hours and especially right before going out the door. I think boys can be trained to sit also - or get a stool to stand or a little potty?
If the diaper was dry when I took it off, it would go back on. They use to sometimes tear were the tape went but I think by my second kid, they reinforced that area really well. But it did tear, I used duct tape to tape it back up.

Hey, each diaper is like 0.30 to 0.50 - it adds up!
Anyways, making them go a few times a day, saved me in diapers, having to change them as much in public, and potty trained them much quicker. Towards the end, I only put them in diapers at night to prevent accidents and if they were dry would be re-used.
Good luck.