It is certainly worth getting another quote. I find the personnel who do the install - it helps if they are friendly. I check online opinions on the company mentioned. How long is the warranty for? For some reason the opener on mine keeps blowing the bulbs(I do install the hd bulbs though). Am in the dark a lot! We have a Barcol 1/2 hp which works well on the two car/single door garage.
Regular oiling helps prevent problems.