So I started it off with about 35 different marquees. It has since grown to over 150 and more are being added weekly. Once a week, I go to eBay and Yahoo and compile information. Then I add in any marquees I saw for sale in newsgroups or web sites. With this information, I update the list.
Some prices go up and others go down.
Plus there is always a handful of new marquees added. In gathering my data, I make sure that the marquee is in good shape. No marquee that is damaged in any way or has a condition rating lower than 7.0 is factored in. Also, I only use marquees that were sold individually. If they were sold in a lot or were sold with something else, like side art or a control panel, then I do not use it.