DVD sale price on this film?

I've noticed that this film has stayed up there in price since it came out on DVD months ago & since then, has never been on sale anywhere lower than $20. Even on Amazon, the cheapest used one is $14 w/shipping. Yesterday I bought movies that preformed much better at the box office for $9.99 at Target & Best Buy like Magnificent 7, Suicide Squad, & Spectre. What is going on with the price on this film? It was a box office bomb that should be in the $5 bargain bin @ Walmart & yet there it sits at 4 times the price its' worth.