Build an Online Store

I have an auction site, built using drupal 7, that is in development. Users post content and other user types bid on the content using comments. The original user who posted the content may then look at their bids through a view, and accept bids. I need: - A flat service fee to be added to the users bid on the product. Before the user submits the bid, the fee will need to be added to the user's bid, and a total price displayed. - add css to display two button fields next to each other. One is an accept bid button, the other is go back - remove save button and add new comment button from comments. I just need these few items initially. I will also need someone to examine why my site issues errors sometimes when content is saved. I believe there is a problem with the structure of a hierarchical set of lists. If things work out with the initial bid, I may need help with this issue as well. Thanks.