The seller pays the broker and while on rare occasions the seller offers to pay the appraisal, the buyer is near always responsible. This is particularly important if it involves lending institutions. You should also know that if this is your 1st home (especially), check out FHA loans which, by the way, allow you to get out of a contract if the house appraises for LESS than the selling amount.
If you have a buyer broker they should be guiding you through this process. First thing is if you have a buyer broker, what does your buyer broker contract say? Most buyer brokers are paid for by the listing agent but some do charge their buyers as well also. If you do not have your own agent, the seller should pay the listing agent their fee. As far as appraisal fee, that is a cost of the buyer, it is not usually paid back. You should check with your loan officer as what can be credited and what can not