Pure failed logic.
ftfy.
It doesn't matter what unit of denomination you keep your books in. The real judge of value is "what can I buy with it" -
at the time you bought your avalon with btc... you could have instead bought 1000 USD or 242 gallon of petrol. This is a valuation of what you spent to purchase the goods. It is incidental that what you chose to buy has the function of generating bitcoins for you. This is called income.
The key is use the same method of valuation for your income as you have for your expenditure.
So what if bitcoins increase in value and have a higher price on your exchange... as long as you can spend some of those bitcoins and buy you 1000 usd or 242 gallons of petrol... as long as you do spend the income.... you've made 100% ROI on your investment.
You're confusing speculation and capital gains with income and expenditure.
That would be right if you bought your Avalon with USD. But if you already had the BTC you invested into the Avalon in your wallet then you have to beat the higher value the BTC gained through the rising worth of the BTC. If you cant beat that value then you have invested 100BTC that were worth $1000 at that time. When the price of a BTC is $200 then you still have to mine 100BTC because if you wouldnt have bought the avalon you still would have 100BTC that now would be worth $20000.
In case the price for a BTC was at the start $10 and at the end $200:
Wallet: 100BTC (=$1000) -> Avalon Worth 100BTC (=$1000) -> Mining Revenue of 100BTC (=$20000)
or
Wallet: 100BTC (=$1000) -> nothing done -> In Wallet 100BTC (=$20000)
So if you only mined the initial $1000 back you would have only $1000 at the end, not $20000:
Wallet: 100BTC (=$1000) -> Avalon Worth 100BTC (=$1000) -> Mining Revenue of 5BTC (=$1000)
Of course if you didnt have BTC from the start and only changed USD into BTC to buy the avalon then it would be this way:
$1000 -> Wallet: 100BTC (=$1000) -> Avalon Worth 100BTC (=$1000) -> Mining Revenue of 5BTC (=$1000)
You would have your initial investment back. But still... if you skipped the investmentpart and kept the BTC you would be richer then.