5% fee means you are essentially paying $1.05 (US) for the HBD (though subject to price fluctuation of HIVE over the next 3.5 days). If you were to buy it from the market right now you would pay about $1.30 so clearly it is better to pay to lower price. Just make sure you understand how the conversion operation works, including the need to lock up extra collateral for 3.5 days.