You always get exactly what you pay for. Unless you know how to rebuild the item you are going to purchase, pass on it.
It could be many things. A lose wire on the plug, wire that is too small to be used, dirt in the motor, if it ran, then the motor is still good. Could be that your outlet is not of good quality to fully support the amount of start current the motor is pulling. The start windings is not being properly switched to the run windings. You just have to investigate with proper electrical tools. Start by using an ohm meter to see if there is a short. Check that the start winding is being switched properly upon the correct rpm of the shaft. Make sure that the brushes are good and not worn too enough to touch more than one circuit on the armature.
Everything about that appliance can be rebuilt. There are electrical and parts manuals on the hobart website. The repair should not be all that costly. This is only a 10 quart mixer. I purchased (4) 1946 model, 100 quart hobart mixers for a bakery we used to own, I went thru them all before ever energizing them. They were only dirty, and a good cleaning of the motor and armature cost me a few cans of electric cleaner. I did replace the brushes while I was looking at them. Nothing beats the good old products that were build by Americans, and not any of the plastic foreign junk that is being produced today. We sold all (4) units and they are still in use today.
Take it completely apart and clean everything, replace what needs to be replaced. Washers, spacers, brushes, etc....