I have a friend who has offered a Para P14 with 2 mags for $550. Looks good but the rear sight is a little loose. If I buy it I would have night sights installed. I haven’t seen one for sale in a while just want to see if this is a fair deal. It is stainless. What can I expect the cost would be to have new sights installed? Also can I tighten up the rear sight without sending it to a Smith.