I found this eyepiece on Amazon https://www.amazon.com/Televue-31mm-Nagler-Type-Eyepiece/dp/B00063G0U0
which means: You don't need to convert your bitcoin to another currency to buy it. Instead you use the purse.io site. Purse.io is a marketplace that links those with amazon credit/points and those with btc together. Those with BTC create an auction and list an item they want by linking a wishlist. They can change the discount on this item so they can typically get it for %15 under the value of the item because someone with the amazon credit/points/coins wants the BTC that badly. It will tell you your chances of success as you change the % of the auction. I had a few go through for 20% off and no issues