I have twice over the years. The first one was a serger someone convinced me I really needed. I bought one, watched the video it came with, threaded it, sewed about 4”, a thread broke. I put it in its case and it sat in the bottom of a closet for the next 5 years until I decided to get rid of it. Sold it for about 1/3 what I pair for it
the second one was a machine I purchased when someone who worked on my Viking told me it was not fixable. I was ( crushed) but needed a machine. Purchased a machine our LQS sold. Absolutely hated it. After dealing with it for a few weeks I pulled my Viking back out wondering just what was wrong- was it truly not working? I had taken it to someone who was recommended for a cleaning. Set it up- it worked fine. YEA! I didn’t have to spend that $800 on the new machine at all...I kept it thinking it would be a good travel / backup machine.
I started teaching some ladies at work to sew and took it there to use during breaks and down time we were making aprons and gifts for residents. One of my coworkers fell in love with that machine- thought it was the greatest machine ever. I sold it to her.