I have had my serger for probably 16 years. I use it mostly when I sew garments or tote bags, barely for quilts, maybe not at all, although I am thinking, it would make my pieced backings stronger.
Since I never got into learning how to change tensions to make decorative stitches etc. I don't use it as much as some, but...what I do use it for is great.
It gets a fraction of use, compared to my other machines, but i would buy it all over again. My humble opinion? If you garment, home dec, sew, go for it. If you only quilt sew? spend your money on fabric. :D