Well, 300 count of 3-1/8 Air filled balls cost about $42.99, so depending how large you want the pit to be, that's how much the balls cost. Do the math.
You can't!
how do you build a deep pit
the ball pit is in the fun house on the left
A fire pit ball used for a fireplace.
500$
No coverage available
It cost 16d, also known as 16pence to sit in the pit. But dont forget you had to stand up.
50
40,000 yearly
A ball pit is a play area intended for children, filled with colourful plastic balls.
$300-$500 too much
around $900 according to cha cha