Can I flash an Iphone 5s 16GB cell phone to cricket?

Ok so I was online and I found an Iphone 5s 16GB cell phone at best buy.com and I was wondering if I could flash it to cricket. It says that the ihpone is with sprint. But after I buy it I want to flash it to cricket. How do I do that? Can I do that? Someone please help me!

You don't flash iPhones. The get unlocked. Unlocked means it is open to use on any network. But your plan is not thought out well. Best Buy is selling the phones for the Big Four carriers. The price you saw was a contract discounted price. Meaning you would have to buy a two year contract to get it. Only then could you try to unlock it but then your credit is trashed for bouncing out on the contract bill.
The best solution is to buy an unlocked iPhone. Yes. They are super expensive but that's exactly why. Unlocked 5S is $650 for a 16b. So buy a used one on Ebay and go from there. Best luck.