>>715917513
It'll definitely give you the most bang for your buck, even at full price. I recommend not looking up any guides until you at least beat the main path downwards.
If you do get it, make sure to disable cloud saves for it as it causes some undesirable behavior in the later game (file sizes get too beefy for it to manage). Also enable the built in killcam if you aren't using an external one. I get a lot of joy out of recording some of my more hilarious deaths.

I'm surprised nobody has managed to solve the Eye puzzle yet