What exactly do you mean by buying a BTC Seg fork?
He asks whether he should invest into the Segwit2x altcoin once it is available for purchase.
The fork is set to happen tomorrow, so if you haven't accumulated some bitcoins in your wallet then now is not the best time to buy seeing that the coin is now priced @ $7000+ a piece.
Source for this claim?
Right now I'm just waiting for everything else to happen and I'd be selling off S2X coins I might receive once it goes live in the exchanges.
No replay protection -> say bye to your Bitcoins.