It has been an institution since 1985. Carter's Price Guide To Antiques In Australasia, totally revised every year, is the authoritative guide to the value of antiques. The 2009 edition is the 25th and has been given a suitably silver-themed cover.

The Carter's guide is a compulsory tool within the industry but has also become popular among the hordes of amateur collectors, who want to see if what they picked up for $1 from the garage sale really is worth something. Weekend traders are also likely to have a copy stored in the back of the van.

If you want to know why it's harder these days to snap up bargains in op shops, you can blame Carter's. Most charity organisations use the publication to check that nothing of great value sneaks through onto the shelves (thankfully, some things still do).

A companion publication, Carter's Everything Vintage, covers the fast-emerging world of collectables, defined as anything produced after 1950. This inevitably includes that pile of junk you threw out last year that is now worth a small fortune. This spin-off edition is in its fourth year of publication.

The format for both books is deceptively simple.

Dealers are invited to submit a selection of their wares and nominate a recommended retail price. In the case of the 2009 Antiques Guide, 650 dealers from Australia and New Zealand supplied a total of 8000 items, all photographed, priced and listed under a general theme. If you are interested in Royal Doulton character jugs, for example, you can look this up in the index and make direct comparisons.

Subject matter ranges from Australian Advertising to Tribal. Individual items are listed in the index - for example, the sole vintage tin-opener listed appears in the Household Objects section.

If you have a collection of price guides, you can compare prices from this year with those from 1998 to gauge whether your collection is increasing in value or not. This can be a help if you are considering selling.

Contributing dealers are indexed at the back according to state, with full contact details. It's worth noting that the prices listed are supplied by the dealers themselves and represent what you would pay if you bought from the store. The competitive nature of the industry means they'll keep prices down as much as possible but be warned, the prices listed are not necessarily what you'll get for an object if you want to sell it.

Dealers will usually offer much less to buy an item than what they can sell it for. They have to make a profit because it is usually their sole source of income.

If you want a general guide as to what the items you own are worth, divide by half and anything you can get above that is a bonus. For those selling antiques, a general auction can often give you better results than selling to a dealer. Auction houses also refer to Carter's to set the reserve price on items they sell. If you can get more than the estimate, you're a winner.

An interesting sideline is that Carter's guides have also become collector's items. Enthusiasts like to have the full set, so the earliest copies have been selling for as much as $2000 each on the secondary market.

Carter's Price Guide To Antiques In Australasia is published by John Furphy ($125). It is available through most booksellers and ABC Shops.

Something for the collector who has (almost) everything

A copy of The Sun newspaper from December 11, 1936, announcing the abdication of Edward VIII. Valued at $18 to $22 from Antiques, Goods & Chattels, Victoria.

A Brisbane tram conductor's tools of trade, about 1930. Valued at $275 to $315 from Scotland Yard Antiques, Brisbane.

A brass NSW Fire Department hose nozzle made by T. Green, Sydney. Valued at $90 to $110 from the Cowra Fun Museum, NSW.

A Pontius Pilate coin, from Rome, c30AD. Valued at $145 to $165 from Collectable Creations, Queensland.

A pair of Betta brand pink quilted slippers, size four, about 1930. Valued at $72 to $92 from Leura Vintage, NSW.

A small Rorqual whale skull from a 19th-century Tasmanian collection. Valued at $9800 to $10,200 from J.B. Hawkins Antiques, Tasmania.

A pin-fire Apache six-shot pistol knuckle-duster knife. Valued at $950 to $1050 from Antique and Modern Firearms, Tasmania.

A cast-iron and oak rowing machine, made in England about 1900. Valued at $1400 to $1600 from Gizmo, South Australia.