Te coins themselves are worth xBTC. Selling them now would only enable you to profit on the premium in BTC which would be greater now than it would be then (after the fork) if the price of BTC were to rise as a result of it.
Personally I don't see the need to. The coins are wallets themselves so post-fork they'd have the value of BitcoinGold added to them which would add to the BTC price if you chose to sell after.
So in short, I'd advise you to keep them and if you want to buy more BTC now then by all means go for it.
I'm wondering the same, FattCatt.
Is this accurate? Are the BTC coins held on wallets that have not given out the Bitcoin Gold worth a larger sum of money based on how much Bitcoin Gold is going for? Example being if Bitcoin is $6k and Bitcoin gold is $500, your BTC is now valued at $6500? Will it reflect that on hardware wallets? Is that how it worked with Bitcoin Cash?