Yeah, but the whole thing about it is that it wouldn't even matter if a DIAS got scratched because it isn't collectable. In a few more years you will be able to buy two DIAS for the price of one factory Colt rifle, even a scratched up one, which is already the case with an A2.
Besides, are you buying this thing to shoot or to help you retire? If the latter, then that should change your choice of weapon quite a bit. I've got a friend with an original Colt Commando in new condition that has never been fired. He paid like $11,000 or so for the damn thing. He really likes it and I'm happy for him to be able to find something that he is that proud of, but I would never drop that kind of money on something that I wasn't going to shoot. I want a rifle that says M16 on the side because that is what [b]I[/b] want. I've wanted one since I was little so when my stock appreciates I'm going to get it. I want the Colt horsey and M16 in big letters, so I can look at it and [:D]. I thought about playing with a link for a while until my dealer talked me out of it, but deep down inside I knew that I wanted a factory gun anyways, so it wasn't hard to talk me out of it.
So basically it comes down to "why are you buying this gun?". Just remember, you are talking about quite a bit of money no matter what your choice. Probably more money than the average [b]sane[/b] person would even consider spending on a gun, so make sure your decision is really your decision or you are going to be unhappy with it.
If you are planning on keeping this thing forever and want something cool to show off to everybody for the rest of your life then spring for a factory Colt. If you want a gun that you know is in spec and will function correctly the minute you get it, but you don't really care about collectability then get a Colt 614 for a little less cash. If you want a shooter that you don't really care a lot about the looks or markings and won't appreciate at the rate of a Colt in the long run then get a RR conversion. If you want something that nobody could care less about how it looks, as long as it works in the gun that they want to put it in, but you can keep the host gun looking new forever, then get a DIAS. If you want the absoluetely cheapest thing you can get by with, that may require a little tinkering to get to run correctly and to keep running correctly, or if you just don't have the money for the more expensive goods then pick up a link. It's better than nothing, but it's still gonna cost you $2.5K at the minimum not counting the host.
Have fun picking out your weapon and make sure you get what [b]you[/b] want, cause your the one that will be stuck with it!