Where is the cheapest place to buy rainbows?

i went to tillys and they were like 50 bucks. my stingy dad wasnt willing to pay that much soo he took me to target and i got a pair of 10 dollar flip flops. he said if i can find somewhere where they sell em cheaper then we can go and get them right now. i need legit answers. also if you can can you give me the url to where you found the price. lots of love to the ones who took there time to read. peace!