I have few suggestions: -Automatically bring up the current bitcoin price without the person having to click calculate. -Add a little more graphics to the site, nothing to slow the site down but a bitcoin symbol will do nicely IMO. -Add a feature for an instant conversion image between BTC and USD (I mean a dynamic image with the equivalent to the specified amount in USD in BTC), an app site site used to offer this and I think it's offline so it would be a great feature for people selling in BTC with a certain USD price in mind.
Price lowered! Going first with anyone trusted. you can buy it at banx.io it's sort of share system, it's currently in ICO and the price is 0.0076 each and I'm selling 10 here for 0.03 BTC!