The best answer is that (in your case)) the buyer pays all the closing costs. After all, with no legal representation, why not take the buyer for all they are worth?
The truth is that the value in having professional representation is that you have peoplel other than principals (meaning the buyer and seller) negotiate. When you are the buyer are talking directly, it's like playing poker.
It depends. Closing costs will be incurred by both sides when you are using a title/escrow company (and you most likely are) and mortgage companies. Like everything else in a real estate transaction, who pays those closing costs are negotiable between buyer and seller.