When evaluating the value of an old toy, the three most important things to consider are rarity, age and condition. If an antique toy is difficult to come by and still in good shape, it is likely to be worth something.
Toys that were produced cheaply and in large quantities are usually worth less than the more durable high-end toys, which tend to be rarer and better preserved. However, sometimes the fact that mass-produced toys were so easy to break means that surviving examples in good condition may be very hard to find. This can make them quite valuable.
Look for makers' marks, country-of-origin marks and patents to determine the manufacturer of the toy and the date. Dating an antique toy is key in determining its value, though older toys aren't always worth more because collectors specialize in a variety of eras and types of toys.
It is very rare to find an old toy in mint condition with its original box or packaging. This is the ultimate goal for any collector, and they will fetch the highest price. Toys in good condition, with some wear or fading paint, may still be desirable, however. Never attempt to restore or repaint an antique toy without consulting an expert, as this may significantly decrease its value.