Instructions
Complete a "fast and dirty" appraisal of the stamps. According to Harry McCulloch, the President of the Glen Ellyn Philatelic Club, you can multiply the total number of stamps in your collection by $.20 for a base (lowest) value assessment of your stamp collection. The $.20 figure comes from the Scott Catalog, the premiere guide on stamp values.
Assess the value of your most valuable stamps. Visit your local library for the Scott Catalog, and look up the value of your stamps. Be sure to check the watermark of the stamps, and pay extra attention to the various criteria to determine whether a stamp is in a Very Fine status (the stamp has no torn corners, is kept in a folder, is dry, etc.). Very Fine stamps have the most value. The "Very Fine" status and others are explained in greater detail in the catalog. Add up the total value of your Australian stamp collection.
Contact dealers with a list of your stamps, and request an offer. The websites of the Australian Philatelic Federation and the Australian Philatelic Society provide two broad membership lists that include a number of prospective dealers. Contact a member or prospective dealer by email with a full list of your stamps that includes your predicted value of those stamps (based on the Scott Catalog) next to statements describing each stamp's physical condition (whether it's kept in a folder, is dry, has been used before, etc.).
Compare the offers you receive and sell to the highest bidder.