Here in the Portland Oregon market Seamless gutter costs vary $4 – $7 per foot depending on style of gutter, materials, method of affixing them, type of application, and roof height. Other considerations may be color of gutters. White gutters are usually the lowest price and many contractors will charge you extra for any other color as their vendors charge more for colors. Due to our volume of purchases we do not incur this increased price for colors so no matter what color you choose we charge the same price. Many of our competitors prefer to sell Steel materials as it is slightly less expensive and they do not have to re-spool their machines if they sell only steel. Also many of them sell to home builders and they are totally about “Low Cost Materials”  also they use Steel Spike and Ferrule (nails) to affix the gutters, which is a fraction of the cost of quality screws or hidden hangers.  Usually the spikes are placed every 4 ft  which is not enough support if the gutters are plugged and filled with water, or should an ice damn occur. One thing to keep in mind there are only 3 major suppliers of gutter materials in the Portland Area and we all buy from one or more of them. The pricing is about the same from company to company.  So if the cost of materials is relatively the same when comparing apples to apples, what makes the price go up or down is the quality of the materials or components that go into the install and the install labor itself. Another factor is proper licensing including liability insurance, workers compensation insurance etc.  With unlicensed installers the price will most certainly be lower as their operating costa are by far lower. The state’s of Oregon and Washington require gutter installers to be licensed, bonded and inured. If you choose to deal with one of these guys you not only have no legal recourse through the State but they are not required to offer a warranty as well. So if you have problems down the road, you will be responsible for the expense of replacement or repair of damage that was caused by their workmanship. Be sure to ask what the warranty is for leaks, gutters pulling away from home and proper water evacuation. These are just as important as the install itself as service when you need it is essential.