Due to the vast amount of model horses available, some hobbyists collect only one kind of breed, scale or particular mold. Most model horses are in the 1:9 scale, while others are no bigger than mice. Usually a model is released in a particular color for a number of years or a limited run. The model horse company may decide to make portrait models of famous horses as well, such as Secretariat and Man o' War. Having a collection of several color versions of one mold is referred to as a "conga line". Hobbyists simply collect what they like, and others may collect in hopes of selling at a profit later on. There is no guarantee that models will increase in value over time. Since the advent of eBay, comparing prices has become much easier, so prices have fallen. Buyers can now purchase a horse for much less than what it was originally bought.