[Jim]

With 12 strings, just like 6-strings, you do get what you pay for. You can find a decent used Taylor 300 series. Their lower series are not going to sound as good as they are laminated/plywood while the 300 and above are solid wood). Or you can find a used Guild from the 1970s which will also be solid wood (so long as it is not a maple one). Guild "GADs" and Guild "Westerly Collections" are not actually made by Guild - they are made in China by non-Guild factories who have a contract to make them for Guild to sell under the Guild name. A guild from the 1970s will have been made in the US and will be a different instrument which in my opinion will be far higher quality in tone and build. Martin 12s are not in the same league in my opinion, especially their laminated/plywood models like the X series you mention. In the end, though, buy what you like and don't be in any rush. Find the one that sounds and plays the best to you and don't be hesitant to take a road trip to visit some larger stores that may have the models that you need to try out.