Normal usage will smooth the parts and make the trigger seem lighter or you can have a smith tune the trigger. I would try to get 500 rounds through it first to see if there are any other things that you want a smith to look at.
I presume you already bought the handgun. $850 seems like a decent price, but, as my nature, I would try to get it cheaper. I wonder why someone would sell a 1911 with so few rounds if there was not a problem or concern.
"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
Life Member NRA
Life Member NAHC
Former President of the ECPT (Eifel Combat Pistol Team)