Replying to AR7's with demo binding +k for help

I am looking to buy a new pair of skis, I was looking at arw's but theyre 100 underfoot so i decided against them but then i stumbled upon a pair of ar7's with a demo binding, theyre unused and seem to be priced right, $500, but im not sure if i should get them. I ski all mountain, and back country but i also ski park alot considering i work as park crew. Are the demo bindings ok, will they mess up my progression in the park? i can adjust the mount either back or central beacuse of the demos so i figure theyd be good when i ski backwoods. HELP PEOPLE