If the price of Bitcoin is taken as the standard price, if the price of Bitcoin is high, no one wants to buy something worth $5 with $50. The pricing problem is difficult to solve,
This is a non-issue. All the items available in Amazon is priced in fiat currency. After they start accepting BTC, it may be possible to pay using your coins. But at the same time, since the prices are given in fiat, the coins will be immediately converted to USD or any other fiat currency once the payment is made. So volatility is not an issue (unless Amazon has an idea to store at least some of the coins they receive for the long term). They may use some provider like Coinbase to process the Bitcoin payments. As soon as the coins are received, Coinbase will convert it to fiat as per the prevailing exchange rates.