Thanks for the reply. I do not know what impacts the cost of these for the M2 vs. M4. I leave that to your experience and expertise. However, the cost may not be an issue for many who are looking for such a part. what is driving it is Part 922r regulations and how they relate to the M2 Tactical model with the pistol grips. The problem is that to modify the gun with additional items such as rails, extensions and other things that make this a bad Foreign Gun as described in Part 922r of the regs, and the the BATF is not able to agree whether or not such additions will put the M2 Tactical over the number allowed "evil parts" (ie: pistol grips, foreign made followers etc). IF there were a full length magazine tube for the gun, it would eliminate the foreign made existing tube and eliminate the need for the extension thus positively bringing this gun into compliance with some room to spare for additional "evil parts" like collapsible stocks!.
Are you familiar with 922r? There is some debate about it related to M2 since the BATF has issued definitive and consistent written statements about the number of foreign made parts for the M4 and exempt some for the M4 since it is the official military gun. However they have not done so for the M2. I have seen different letters from the BATF that shows different counts of "evil parts" on the standard M2 Tactical. I know that this has never been enforced but the last thing we want to worry about after defending my family and home is some smart Lawyer who will bring this up and convince a jury that i am some kind of militaristic freak waiting to kill someone for having a non-compliant gun with too many evil parts.
What all this means is that people might pay more for the part. I agree $250 is a bit steep but maybe there is something that can be done about that. If you would like to share the design concerns with me in a PM maybe i can make some suggestions or brainstorm some solutions.