Bitcoin satellites - Bitcoin Gold(BTG) and Bitcoin Cash(BCH) - Buy Opportunity ?

After the big run of BCH came a decline to about $1200, BTG about $250,
is it a buy opportunity?
I think yes, even if those coins don't replace the main Bitcoin(BTC), yet they are
kind of Bitcoin, so even if they get %50 of the BTC price, its still nice profit.
So I try it out...
Of course, this is not an investment advice, just my thought :)