When it comes to gutters a lot of roofing companies see it as a waste of time unless they are combining it with a Re-roof or new roof. Even then the guys on the job usually just put new brackets in the same holes or even use the old brackets, even cutting the back out of the gutter so fits perfectly in the same place. It is the attitude that customers won’t be able to tell the difference. I will say there are home owners who thinks a similar thing “there just gutters”
One thing you have got to understand is that houses can move over time depending on what sort soil the house is built on. But because of this gutter need to be re-falled or re-angled towards the downpipes so the water can get away and not sit in the gutter. This means drilling new holes to fit the new external spiked brackets or adjusting the internal brackets up or down to get the correct the angle.
Also be a where of other problems that gutter fixers have to face. Some old houses have the back of the metal gutter folded and nailed over the fascia board then the roof put on top (very hard to get off if you not replacing the roof). When bracket break off people can screw or nail the gutter to the fascia board. We can remove gutters to find that the fascia board is not fixed to the end of the roof truss. These are just a few of the problems we encounter.
When getting a gutter quote does someone come over check the gutter, see what access they have and what problems might be involved and then bases their price on that or do you get “well I looked at your house on goggle earth and I reckon I could do it for $$$$ see cheap as chips” and 9 times out of 10 that is exactly what you will get a cheap job. Don’t get me wrong, price is an issue but if you go for the cheap and nasty you will be paying for it not too far down the track.