I think mainly it's becoz of the difference in price and quality. I doubt Davis will import a Samick for you right? Edwards and ESP are Japanese made high quality stuff, while LTD is mainly Korean mass produced stuff. The LTD series, as far as I understand, are Korean copies of the ESP series, something like Fender and Squier I supposed? But is much more complicated considering the sheer no. of lines ESP guitars are branched into. There is the main ESP line, the highest quality in craftsmanship ESP has to offer, there's the Edwards line, still high quality Japanese guitars but slightly inferior due to material and pickup diffs, the navigator line, where rare woods are used, the grassroots line, which is the original cheapo line for ESP, meant for beginners, and finally, the LTD line, which was originally intended for non-japanese markets but in recent years made its way into Japan as well.