Thanks for the help guys.
Since my system is working with dollar amounts, the penny makes a difference. Additionally, no item will cost half a penny, or break the two decimal barrier. However, to make sure it doesn't, I decided to create my system to remove the cents if it's not going to affect the deduction, then append them after the arithmetic calculations. If the price affects the account balance's cents, then it performs the calculations as normal. This seems like it's working excellently and performed all sorts of testing.
The entire system would have been easier if the user didn't have 2 different balances, one is the deposited amounts, and the other is the earnings they make on the site. Since purchasing allows them to use both balances it makes everything more difficult.
I will continue testing my system with different senarios and see if it's the ideal way of doing things, otherwise, I'll go with the arbitrary precision library.
Thanks again for the help.