Business class gives you direct access to staff help - sorry don't have any more details than that. Business Class is a new upgrade just launched.
The site linked to my name has domain mapping and no ads upgrades - $ 43.-- / year. My needs are simple and the stock themes are fine for me.
My old host charges me $ 60.-- / year for email on two domains - I have several email addresses with the account. My old host is a small local company - their pricing is in line with the large companies for the same package.
The staff checks the forum on a regular basis - most of the questions are answered by unpaid volunteers. When we can't give a full answer or are not sure of something we flag it for the staff to review and help.