A Value Resort, such as PC, during Value Season will be about the same, and can be less, than staying off property. Unless $5 - $10/night makes a difference to your budget, then I recommend staying on property. You will be a part of the magic every waking moment, and no one delivers service like Disney!
I've stayed at all of the Value Resorts and most of the Moderates, and [to me] it comes down to how much time you will be spending at your resort vs in the parks. If you will be taking a toddler back for a mid-day nap, then the moderates might get the nod. However, I have never been disappointed at a value. PC is the newest, so I'd recommend giving it a try. Enjoy your stay :wave: