things to look for when buying a welder is first, know what kind of welding you want to use it for the most and what kind of conditions you will use it for. a welder that gets used for long periods of time needs to have a good duty cycle so it doesn't burn itself out. duty cycle is how much time it can be used for continuously. if you are doing assembly line work where the parts are already fit up so the welder gets actally used almost constantly then that would be a far better duty cycle than the home shop guy that has the welder on but spends a lot of time fitting up parts and less actual time running a bead.
here is a decent blurb on welders from bakers gas
https://bakersgas.com/blogs/buying-g...r&gad_source=1
you should also look at the little things like how long the cables are, what the ground clamp is like, if the consumables are easily sourced like gas cups, contact tips etc. I'm sure everybody would like to buy a new miller, lincoln or a big brand name when looking at new stuff but not everybody has the budget for that.
I bought my everlast because I was talking to a owner of a shop that had previously been using a big brand name welder. it was old an he finally broke down and bought a new one of the same brand name. it didn't last a day so they warranteed it. the next new one burned up due to an electrical power surge in the area from the utility company, they warranteed it but it took some time to work through the system and actually show up so he bought an everlast unit. power mts 275. when the new brand name welder showed up he put it in storage because he fell in love with the everlast one and has used it day in and day out for several years with no problems. that spoke volumes for me so I bought the everlast over the big name one I was looking at. quite a bit cheaper as well.