$400 for any milspec model is about average. Be forewarned that the mil-spec models will not be as high quality as their "Loaded" models. They are usually made in South
America by Imbel. If the gun can be tested or the seller is willing to offer a refund should there be excessive failure of the weapon, then take it. Firearms are always subject to some hit and miss (no pun intended) when it comes to quality. It is the nature of hand crafted items. However mil-spec 1911's seem to be more hit and miss than others.
Also, make sure you like the sights on the milspec. They are tiny and not smoothed to be snag free. If it works and you are just using it for recreation, go for it. If you want it for carry, the sights will sometimes snag and the frame and slide probably haven't been contoured to be CCW friendly.
You might be better off saving a bit longer for a "Loaded" chammpion size or full size or that SIG. I used and carried a SIG for a number of years. I loved it and it served me well. However, recently I switched to a 1911 (the full size "Loaded" from Springfield) and honestly I wouldn't go back. I loved my SIG, but it just doesn't compare to the 1911. The 1911 just fits perfectly in my hands.
That being said, the SIG fit my hand better than any double stack pistol I have ever handled. Better than any Beretta, Glock, S&W, and especially the USP (compact and full size). Of all double stacks, the SIG 226 was the absolute hands down winner in feel, fit and function. However, the 1911 is the absolute best of any gun, single or double stack in my hands.
All in all,it is up to you what feels good and operates well and easy to you. I don't mind flippiung off the safety when I unholster the 1911. You might. I like the thinner grip of the 1911, you might not. You might prefer the double action over the single action/thumb safety combo. Either way, you will have a fine weapon.