As other say, better safe than sorry. I would think that if BTG becomes available by the time of the fork, there will be a steeper increase of BTC (ad BTG will be dumped for more BTC). So in that way, BTC might be quite "cheap" now.
BTG fork is already ended without even miner impact on BTC , He is talking about the SegwitX2 which is still to come this month .
@OP fork = free money but not necessary = profit . For example you buy BTC at 6400 for fork and get your free coins , BTC insta dump to 6000 and the new coin worth only 200 . So you bought with 6400 and ended up with 6000+200 = you lose 200 . You got your free 200 but still lose money .
P.S
This is just an example but the reality is you have a much much bigger chance to make profit from fork than lose money .