The advantage of a manual vs. a computerizes is that you can usually do all the servicing yourself, short of broken parts. A computerized machine has a lot of features not available on the manual. I know plenty of people who were perfectly happy with their mechanical brand name machines and have never upgraded to a computerized one. I love my computerized Bernina, but the upkeep will also be higher since most things must be done by a technician.
BTW, my sister got a mechanical Bernina (990?) at an auction for $100. She cleaned and replaced the oil. Runs wonderfully and so much more quietly than her other machines. This is perfect for her since she is 45 miles from the nearest sewing repair person.