I think you should be able to do that, but I do not recommmend that, BitPay allows you to pay on some websites though not all as I was able to pay for my domain name and hosting on namecheap using btc, also Amazon allows you to shop with BTC, but think about it, you buy stuff of $100 with btc this week and you pay with coins and then next week the coin has increased in value from $100 to $150, isn't that somehow, I would advice you just hold on to your coins and then shop with real cash.