We can set the price to any hash rate but, in order to maximize the adoption of this pricing scheme, we need to set a price that is close to the current market price. According to blockchain.com, the last recorded hash rate was 90M TH/s and before that it was 125M TH/s. We can generalize it to 100M TH/s. The price has also moved around $10k so I'll use that.
(100M TH/s)/($10k) = 10k TH/s - and this becomes our standard unit. Now the price is directly tied to the hash rate.
What's the price of BTC? Simple- (current hash rate divided by 10k TH/s) * $1.
...
at 1M TH/s, 1 BTC = $100
at 10M TH/s, 1 BTC = $1k
at 100M TH/s, 1 BTC = $10k
at 1B TH/s, 1 BTC = $100k
...
Not only is this a fair and stable pricing scheme, it encourages mining, which increases the hash rate, which increases the price. And that's what we want because it will maximize security.