Hi. The difference is what was done in the factory and priced accordingly. Trigger, sights, etc. There all the same pistol otherwise.
However, the ammo used matters too. A Gold Cup is a great, but high priced, target pistol, if you use poor or mediocre ammo in it, it won't shoot well. Mind you, that applies to any handgun.
The finish doesn't affect how well any pistol shoots. The grips are a personal feel thing. Changing grips is not a big, expensive deal. The sights are a different thing, but still not a big, expensive deal. There's more aftermarket stuff for .45's than any other firearm. Most of which doesn't cost a month's rent/mortgage payment.
Look around for a used Colt Government Model, Series 70, pistol. It'll will be used, but that doesn't matter. (It takes an incredible amount of abuse to damage one.) Have a trigger job done, if it hasn't already been done, and put on a set of adjustable high visibility sights, again, if it hasn't already been done.
Mine shoots extremely well with 230 grain cast RN's using 4.5 grains of Bullseye. Mind you, I reload for all of my firearms. If you don't, shooting factory gets really expensive fast and you'll have to try a box of as many brands as you can to find the ammo your pistol both shoots well and cycles the action. Few factory loads won't cycle the action, but shooting factory jacketed ammo isn't cheap. Walmart does sell reasonably priced ammo though. Won't necessarily be the most accurate out of your pistol.
