Sounds like it, but maybe not.
You do mention new tires all the way around. Figure a minimum of $600 there, so now you're down to a $1600 tractor right off the bat.
Every tractor has problems you work through them and keep going.
My advice is to put the money right out of your head right now and never think about it again. Maybe you got a good deal and maybe you didn't. If you keep beating yourself up over it you'll never get any enjoyment out of the tractor and that stinks.
Change all the fluids and grease it real good. My Super M always groans a little more when the rear axles haven't been greased enough or it hasn't been run enough. It gets quieter after grease and about 15 minutes in the field.