A word about brand new machines...
A lot of the (less expensive) new machines are considered disposable. What that actually means is that they are not built to be serviced- or easily serviced. In reality what is means is that they are near impossible to open up. There’s no easy access to the belt area nor is there easy access for removing the front cover. (It’s possible to open them up- however it’s not easy and not always without damage to the case. It would be done under extreme conditions.) As a result, most of the times it’s cheaper to buy a new one than to fix it. That’s really sad. Also, for routine servicing- most of the time, these machines only cleaned, oiled and inspected in areas where the tech can easily get at- behind the front cover, in the bobbin area, and under the bottom cover. You can easily do this yourself
Bottom line- research/ask about the serviceability of a machine before buying it. Be cautious of buying newer machines second hand (especially if they have problems) as you might end up with one that you can’t repair. Do your research on the model in advance.
Machines from the early 2000's are ok
While machines from the early 2000's do have plastic parts, these machines are generally built to be serviced and there's either lots of donor machines or parts around if needed. It's best to give these machines a good once over before purchasing- does the handwheel turn freely or is it "sticky"? inspect the power cord for damage, then plug it in (if not damaged of course)- does the motor run? does it sew properly? does it reverse?
Be careful with 1980-2000's machines
Machines which I from 1980-2000’s era- although they are easy to open up and service- what I’ve seen a lot of is plastic that is starting to degrade. Sometimes parts can be replaced- it depends on the make and model and if you can find a part. Make sure you do a very good inspection on these machines before buying them. Open covers and look at the gears in particular. Look for cracked hand wheels.
Stay away from gimicky options like self winding bobbins. Those machines are a real PITA. If it’s not something that machines have as a feature now a days (and those features have been available for some time and machine makers still keep putting them on machines) it’s likely gonna drive you crazy.
You can't go wrong with vintage (for the most part)
My hands down favourite for machines that have a few stitch options are pre 1980’s- preferably even slightly earlier (maybe from the 1960’s) Why? Because they are easy to work on. Most (many times all) of their inner parts are metal. Unless a part is damaged (like a bent bar or something) it’s usually just a good spa day that the machine needs. The average person can easily perform maintenance in these machines. It does come with fewer stitch options sometimes so it’s a trade off. But I’ve sewn leggings and other stretchy materials on these machines without issues.
The Vintage/Antique straight stitch are both beautiful and functional
My love for the very vintage/antique machine will never die. Why? Stitch quality and the quality of the machine- and they easy also easy to work on. If you just need a straight stitch machine those beautiful vintage/antique machines are for you. My Grandmas Singer 201 will always be my all time favourite. Not just because it was my grandmas machine but because it is strong a reliable.