Yes, we have a chair lift in our house.. We have an "A" Frame house which means the bedrooms are upstairs..
It is a Bruno model and we had it installed about 3 years ago..
It is the most wonderful thing.. We use it every day at least 4 to 6 times.. 
I have had 2 hip replacements (and a shoulder) and my wife has sciatica.. Without the chairlift, I don't know what we would have done..
The cost??? We got a grant from the government (cost nothing) but if we had to pay, it would of cost about $3250 installed (with the fold-down rail) which isn't bad.. The maintinance is nothing.. Annual check-ups are free including greasing and cleaning the track.. The batteries should last for years and they are $35.00 to replace.. The unit has a 3 year warranty.. The motor has a 5 year warranty.. These units should last for about 10 years or more depending on how many trips are made up and down..
Our staircase is wide enough for someone to walk up with the lift there.. The unit folds up to give extra space anyway.. We have a fold-down rail at the bottom to allow for the front door entrance to have extra room.. That is an extra option.. Again, it is an "A" Frame which is a bit different to the average house..
I did shop around and ask questions about the different companies and found the Bruno to be the best machine.. Yes the instillation is always custom made.. We have NO intentions of selling the house, but should we sell, we will just include it with the house..