I built myself one and love it. Makes me want a full size one now. Cost me about 250 to build but I bought all new steel.
The main thing to building one is take yur time on fit up and make sure everything is square and plumb.
Just got done building mine mashed some 1" bar and made a calla lilly from a rail road spike, next Knives.
I bought me a 20 ton press from Harbor Freight about a year ago and Im finally working on converting it over to an ele motor and pump and I got rid of the bottle jack and put in a hydrolic piston .. Im almost done with it . Ill post pics when done ..