Here they are on Amazon:
They are a little bit over retail price, but not too much higher.
Cheaper on Walmart.com though:
Well I don't know exactly what to call it, but I agree it's not technically a pre-order. When I made my orders none of them had an estimated release date at all. It was similar to what the *slime sets say now:
"Temporarily out of stock. Order now and we'll deliver when available. We'll e-mail you with an estimated delivery date as soon as we have more information. Your account will only be charged when we ship the item."
I ordered those June 3rd and there is still no dates given. https://www.amazon.com/gp/product/B07DFZFY4D/