the price is going to depend on where you are. you are going to want to get 1/8 ounce or 1/4 ounce. it could be as much as $50 for the 1/8 and $100 for 1/4. joints or blunts are the best idea for first time experiences IMO. youll probably be fine with 1/8. roll up 2-3 sizable j's and by the time the third one rolls around im sure the effects will kick in.

here is a thread called "what should an 1/8 look like?"