I don't think I'd get worked up enough to sell a barrel because it has the wrong post in it
. You can change it out in less then 30 seconds, not much more complicated then tying your shoes. Just push the front sight detent in and unscrew the post, insert new post and screw it down in.
Now the front sight base I can understand, but I think people over complicate it a little as well. I doubt it'd be as easy using one with the holes already drilled but using a virgin barrel/base it's relatively easy. All you need is a 8/32 tap and set screw, and a drill press and 2/0 taper reamer and drill bit. This was actually even easier then I thought it'd be from reading everyone else making a FSB install into a big thing. This is what worked for me- I installed the barrel to receiver, slid the FSB on the barrel, turned it upside down and sit it on a level surface. The carrying handle sits on the surface flat thereby aligning the FSB level with it. No fancy tools needed there, then I installed a set screw into the hole above the sling swivel hole and tightened it to the barrel. This allows you to go sight in the rifle first before pinning, although I found it unnecessary as it was already aligned well from sitting it on the flat surface with the carry handle. Then you clamp it level below your drill press and drill through the front section, then ream it and install the taper pin, remove the set screw and do the same to the rear.
You can not see where the base was threaded for the set screw since the sling swivel goes directly below it, but even then it is the same size hole and not really noticeable. This was also the first time I used a tap and it was very easy, just clamped the FSB level in a vice and turned the tap into it a few times with lots of oil and it was done. It's already the correct hole size for 8/32 tap so no need in drilling it larger. I know this was slightly off topic but maybe it can help someone else that is unsure of trying it themselves due to everyone acting like you have to be an expert machinist to install one and pay others lots of money to do it. For someone who isn't used to doing any work with their hands then I'd advise against it but for most it should be very doable.