We needed a loft ladder, so I had a look in the yellow pages and on the web. Then I looked in the local newspapers for builders that would install them, you know what there isn't that many, in fact loftshop seem to have a large section of the market in selling and installing ladder the UK, so that's who I used. There was when I used them, alas a long waiting time before the surveyor came out, and when he did, our notes got lost, they seemed to not want to bother with us, I got fed up and didn't call them again for a year. A year later, we still needed a ladder, so I phoned them up again. This time round things went much more smoothly.I wanted a wooden ladder as the metal ladders gets colder quickly in the winter, and the wooden ladder had a better tread depth. The ladder was a 3 section timber ladder that folds back onto itself so takes up less room in the loft and it cost including installation around 300 pounds including the pole to grab the hatch hook to get the ladder down.Getting up and down the ladder is quite simple, our ladder didn't have a handrail but that doesn't seem to be much of a burden, and the installer did a tidy job so no damage to the ceiling.
In my view it is well worth getting it installed unless you really know what you are doing, I am sure installing a ladder isn't complex, however it's not something you would do on a daily basis, so you might as well get the experts round unless you are really trying to save some money.