My husband surprised me with a Kenmore Sensor-Sew 30 years ago when I passed the CPA exam. It was the worst sewing machine ever! I gave up sewing for many years, simply because I didn't have the heart to tell him what an awful machine it was. Had it serviced numerous times to fix the tension, but it never worked properly. Since I desperately needed a working sewing machine, I purchased a cheapo one for about $250 about 20 years ago. 15 years ago I got back into quilting, but the cheap machine would not sew through denim or more than 3 layers of fabric. The motor would also slow down and need to be shut off to cool down quite often. I read lots of machine reviews and finally ordered a Brother embroidery and quilting machine about 12 years ago. It wasn't cheap, but it still works like a champ!
Ask your wife to decide which machine she would like to have, and then you can order it for her. To me, a sewing machine for an avid quilter or seamstress is a very personal item and needs to fit her needs. I absolutely love my Brother sewing machine. Found one on Amazon for my daughter for about $600 that can handle up to a 5" embroidery hoop. My daughter loves that machine as well.