If it's an MP40 (no wireless at all) I wouldn't spend more than $200 and probably would rather see it in the $150 range for a 3 year old one.   There are so many potential issues with the old vortechs that can end up being a money pit,  new power supply $50, new magnet $20, new motor if it makes sound $175 (or whatever it is), so you got to be damn certain that you're not paying the price of a new one with all the bells and whistles ($450).    I have bought my share of used vortech equipment from people within the club (trusted sources) and all of them needed some sort of repair($) within a month.