I've had a few of the M45A1 Decoms. The last one I sold was the earliest known serial number 01022EGA. It went for 15k...I'm starting to think I let it go too low.
The mint condition guns will ALWAYS bring more money, this is easily seen in older Colts and has been that way for decades. Three words when dealing with high end firearms...Condition, Condition, Condition!
You might be able to still find one in the 6-7k range...but you need to be vigilant and jump on it when you see it...Good luck with your search.