1. As mentioned by others, comm is 2% for seller's agent.
2. As outlined by CEA, all agents have to cobroke their listings. Best way to test your agent is to call and ask for cobroke after he starts advertising your unit for sale. Depending on how he answer your questions, you will be able to know if he is working in your best interest.
3. An agent who meets up with you the first time should not be too concerned about the selling price. What he should be concerned is your financial interest, and others such as your reason to sell, your plans after selling etc. Seeling a property is more than just the selling price. Selling price is "about there" as unless your unit is superbly good or superbly bad, the market is currently at $30k +/- COV.
4. Of course do check HDB website and online property portals for a rough estimate of the selling price in your area.
Just my 2c worth of personal opinions.
Hope the above helps.