Use both bid and ask price where appropriate

[jamiewade]

When you are getting the price of a coin, you always get the bid price.

That is not correct though. The bid price is the price at which you are able to sell a coin.
It is however not the price at which you are able to buy a coin, that's the ask price.

You need to make two different methods for that. One for getting the buy price and one for getting the sell price.