Well, don't buy one just to save in case of this or that. I did that in May 1994, right after the house passed the AWB (but before it went into effect - I panicked). I bought the last Colt in Cincinnatti Ohio at that time and paid a premium ($1200-1300 as I recall), AND was a student at the time so I charged it and paid interest for God knows how long. I still have this weapon, still unfired. Shot the others during the ban. I've been thinking of going out and shooting it in celebration of the end of the ban but haven't even done that yet. The fact is, I realized during the ban that these weapons continued to be available, and there were many unfired "pre-ban" weapons like mine that guys were willing to sell. Those same guys are stubbornly still trying to get $2000 for their "Pre-ban" guns at the gus shows too. In reality, I think those guns are not going to be worth much more than the going price for a post-ban gun before long, after market forces settle in.
If you want a good "investment" try the stock market. The average annual return is 10%. In the 10 years during the ban at that rate, my $1200 that I spent on that gun would now be worth $2438.00 (assuming that the market did not have strange fluctuations, BUT ALSO assuming that I never paid interest on teh $1200 AND that I had no other debt that was accumulating interest during that time). AND this doesn't account for inflation! So anybody who buys something like a gun or a watch or a car, or just about anything as an "investment" is just utterly ignorant of basic economic principles (valuation, interest, capitalization, inflation, etc), just like I was at the time. If I had invested that money in the market, I could now buy that "pre-ban" colt, AND a new 6920. AND, had the ban not ended, I could have still bought a "pre-ban" whatever, and put an M4 upper on it, etc., etc., etc. And all this time, I never even shot the gun!
Now, it's hard to put on a value on the joy I got over the years having that gun in the safe, and fondling it and the like, but imagine the joy I would have felt cashing in that $$$2400 and going out and buying TWO instead of ONE!
Bottom line: NOT A GOOD INVESTMENT. INVEST in the STOCK MARKET then BUY TWICE AS MANY GUNS TO SHOOT!