The average cost of 6” gutters ranges between $1,000-$1500 for the same, 2,000 square foot home. Average cost of gutters per foot for 5” gutters is between 5-8 dollars and for 6” gutters between 8-10 dollars. 5” seamless: $800-$1200.5” cost per foot: 5-8 dollars.6” seamless: $1,000-$1500. 6” cost per foot: 8-10 dollars. There are several reasons that account for the variation in the price of seamless gutters.ere’s a cost breakdown for a standard 2,000 square foot home: For 5” seamless gutters on a typical home (2,000 square foot raised ranch or cape) the average price of a gutter installation ranges from $800-$1200. However with more unpredictable weather, many homeowners get a free estimate for 6” gutters.