correct me if i'm wrong, but it doesn't necessarily have to be in that order, or that way. the 2% booking can be used as a general guideline though.

Example...
If you are selling property around RM200k...
...You can ask for 2%, which is RM4,000.00, or you can ask for more, or ask for even less if both of you are agreeable to mutually agreed terms & conditions before hand. I don't think there are any hard and fast rules when it comes to booking fee cos it depends on the circumstances and what was discussed and agreed upon between the buyer and seller. Remember to ink (put in black & white) the so-called mutually agreed terms & conditions in the presence of a witness (can be your witness or his witness) It will help clear confusion and potential disputes if they arise in the future.

Looking at your scenario, I suggest you get the other co-owner to agree to the transaction first. Spare everyone the trouble and misery later. If I am the buyer I would not give any cent for booking fee if the seller is double minded or not sure. You need to be fair to the other person who intend to buy from you too. Your co-owner may be able to get someone who is willing to pay higher, likewise the buyer may also be able to find another property which is cheaper. I'm sure you or your co-owner will not be happy if the buyer suddenly ask for the booking fee to be refunded.

If I am the seller, i will put in black & white and inform the buyer that once the selling price and other terms is agreed upon, nothing is refundable be it booking fee and especially the 10% paid during signing of S & P.

Looking back at your scenario, i suggest that you get advise from the proper people i.e. lawyer. Later on once you have had more info and experience you'll be able to find your way around quite easily. The first paragraph in my reply is not recommended for people who are newbie to buying n selling property, although I'm not an expert either. Best wishes...