That’s good call taking it to the shop; there’s no foul in your recognizing you don’t have the experience or tools to get it back running by yourself. Better off paying someone who does.
Is it a 98 or later? Your big Foreman will need oil change & filter, air filter clean, clutch adjustment, valve adjustment and battery install. If you can afford it get a brake fluid change and brake adjustment. Then have them change the oil in the differentials. It could run $325 but well worth it.
In top shape you might be able to get $2800 for a 98 450ES depending on local market; NADA value looks a little low.