agree with ian in vic, bought a colt series 70 in late 70's, and spent another $500 to get the damn thing to shoot and function reliably, and replacement sights, etc.
what is out on the market are of good to exceptional quality for the price.
for a basic 1911, my list of must have would be as prproulx said, minimum decent sights (fixed or adj), reliable ejection port, and i would toss in a beavertail grip safety and ambi sights, if buying a "basic" gun to use "out of the box"
to do these above mentioned add-ons, or mods later, is very costly.
take any $ saved and spend on good high quality mags.
anything more than that would strictly be for cosmetics, bells and whistles, and other personal preferences. regards