Based on my last purchase in 2004, the builder quoted $1.5K for medallion at the foyer but I decided to get in done after closing due to few choices of style and color from the builder. Anyway, I got it done for about $500. The cost of medallion was about $400 and labor was $75 + couple beers.
On the same house I found it cheaper to upgrade the floor tile with the builder. The builder’s standard for the home was 12″ on the first floor and the upgrade to 18″ with diagonal setting only cost about $1800 more and covered additional areas like: laundry room, and 2 bathrooms on 2nd floor.
The bottom line is depending on the upgrades and some builders willing to negotiate on the price. You just have to do your homework and be flexible in dealing with contractors.