Collectors put down the most money for world maps and American maps, followed by maps of Southeast Asia, Australia and the Philippines, Chris explains. Interestingly enough, European maps are some of the least popular. Collectors love some state maps more than others, which drives up their price. I'd pick maps of places that most collectors pass over, such as those of France or maybe world trade maps from the 19th century. Some state maps, such as Texas, are more expensive than others.
Collectors also prize specific regions or cities.
Low demand for Pennsylvania and New York state maps makes them a bargain while high demand for New York City and Philadelphia maps drives up their price. Anyone who is serious about collecting maps should plan to do a little research. Important historic changes, such as a border change or the establishment of a major city translate into important map features. Sometimes map enthusiasts will collect a series of maps from one area to trace its development. You can reduce your purchase price even more once you decide what you can live without.