Replacement screen for ideapad U450p

[blynch]

My sister has a 1 month old U450p with a broken screen. She claims she has not abused it in any way and the black blob just appeared one day, lenovo will not cover the screen under warranty. So I'm looking to potentially do the replacement myself, as paying for the job would probably cost close to a new laptop. Where can I get a replacement screen for a reasonable price?
Thanks