Capital gain only counts when you cash out to fiat, currently there is no clear rules when you exchange it with goods
This is challenging for accounting. Imagine that you spent 100 coins at the beginning of the year ($1500) in your business and get a return of 10 coins at the end of the year($9000), then your result is a loss of 90 coins, you should get a tax deduction of 90 coins, which is $81000

However, if counted in USD, you have a net gain of $7500, so you have to pay income tax...