the only part i don't get is why make the pants so you can't wear them post-pregnancy? just make that band and slip it over the pants without cutting them, and then you can still wear the pants after you have your baby.
Because they've invented those. They call them Bella bands. They are horribly uncomfortable, and then you've got what looks like an outtie in a stupid place from your button. They slip and slide and you have to constantly adjust.... annoy as all heck. Doing a recon like this is budget freindly and you don't have to worry about things being uncomfortable and adjustments to your pants/belly band.
Just my experience with those, maybe other people like them. I don't. that is my very honest answer.