ok i was looking at a website and i saw some DENDROBATES AURATUS GREEN AND BRONZE TADPOLEs

(yes i copied and pasted)
for only 20$ and all i could find is from this website and other places that has the frogs they are anywhere between 80$ and 95$ now i know that froglets are real hard to take care of at first but after a few months they get hardier and easier to take care of so would it be like red eyed tree frog hard? or something lower?
and how i have to pu them in a smaller space for about 6 months can i just put a piece of card board or something to make it so they cannot go where ever they please through the tank


thank you