Higher total games lead to slight shading of the ML. Usually not all that noticeable though, but it certainly makes sense to give a little more thought to money line when betting a game in a high-scoring matchup or park.
When doing your comparisons and trying to get a feel for how to approach this, be sure you are thinking in percentages, not cents on a line. At -200, 20 cents means little in percentage terms. At even money, a 20 cent move is a big jump in percentage terms.