For day-to-day sewing you won't need a really fancy expensive machine. I bought a Frister Rossman Cub 4 just over 30 years ago and was in the same dilemma last year when it ceased working. When I thought about it, the stitches I need are straight, zigzag and button holes. The Cub 4 does a three-stage button hole and you don't need to turn the work around. The presser feet I use most are just the normal foot and the zip foot.
Research showed that the Frister Rossmans of this vintage were better made than some of the modern ones and are well-regarded even now, and I decided to get the Cub 4 overhauled professionally, although there were a few more internal bits wrong than originally thought and it took longer to fix. In the meantime I bought a second hand Cub 7, same but just 10 years younger to tide me over, so now have the luxury of two machines :) which see to my modest requirements admirably.
I agree that John Lewis is a good place to go. They have a good range of machines in every price bracket to suit every kind of stitching.