Well,,, the gun has a set of the "Micro" aftermarket sights on it. Many folks enjoy that variation. It's a bit desirable because of the Micros. THe condition of the gun looks pretty goood, but if I were a buyer, I'd want a close-up inspection of the gun.
Next, the pics of the stags looks like they COULD be factory. Again, close-up inspection is in order.
Why?
As they say, the devil is in the details.
Condition is important. As is a "complete package." (Box, papers, shipper, original sights, any documentation about the changing of the sights, etc.)
The gun appears to me to have a bit of wear, but not abuse.
The stags could be factory, could be aftermarket, (or counterfeited to look like factory,) so it does affect value.
JUST from the pics shown, assuming the stags are factory, I'd place the value in the $800-$900 range. Of course, if I was buying,, I'd want to get it cheaper than that!