Let me break it down for you.
"Hillarious! But on a side note.. the only way I'd get the XBone is if it was given to me, and I already had a ps4 so returning it for money to buy a ps4 was pointless."
Hillarious -> Meant as a sarcastic response to Nik saying not funny.
But on a side note -> Meant to add to my comment, to bring another part in that is of a more serious tone.
the only way I'd get the XBone is if it was given to me -> Means.. I would never buy one nor have someone lend me money to buy one/never ask for one
and I already had a ps4 so returning it for money to buy a ps4 was pointless. -> Means, that if I got a XBone then the only reason I would keep it was if I already owned a PS4 making a return of the Gifted Xbone for money not worth it, as it would have gone towards buying a ps4.. but if I already own one, I won't need any money.
Did that clarify things for you?