Those simple die-cast models of cars, trucks, fire engines, fighter jets and all manner of cool and exciting vehicles can make a few bod, reports  Olivia Kelly

What: Dinkies! Die-cast models of cars, trucks, fire engines, fighter jets and all manner of cool and exciting vehicles. These toys, largely made by Corgi, became extremely popular in the 1960s and 1970s and remain so today.

To buy: Most new models retail at €15 to €20, but can cost up to €100. Older models, if you can get them, cost anything from €60 into the thousands, depending on a huge number of variables including the particular edition of a vehicle, colour, the condition of the box and the owner's willingness to sell.

To sell: The new stuff isn't going to have an impressive mark-up.

At this stage, the importance of keeping dinkies and their boxes in mint condition is well-known.

If you have an older model in perfect condition, you're still more likely to get a €60 to €70 return for your 10 shillings spent in 1964 than a figure in the thousands.

Best buys: As a possible investment for the future, look for TV and film-related items, such as James Bond cars or the Monkee Mobile, from the Monkees TV show. Models that come with limited-edition certificates are more likely to be worth something in the future.

Pitfalls: Don't even bother rushing up to the attic to rummage through your barrel of well-loved dinkies; they'll be worth nothing. Models need to be immaculate to be worth anything at all.

What the expert says: "Keep them in their boxes or if you're putting them in a display case, store the box carefully. In the case of a couple of cars from the 1960s, the box is now worth more than

the item," explains Mark Cuffe of Mark's Models, 14 Hawkins Street, Dublin 2.

Contacts: Model Collectors Gazette and watch out for "swap meet" posters in model shops.