The component cost of just about ANY keyboard has been the least of its' value. We have ALWAYS paid for the content, the sounds, the styles, the OS...

Buy an 'open' arranger, and you haven't YET paid for the content at all (at least none able to rival the closed ones). You will STILL have to fill it yourself, at your considerable time and effort (and what is THAT worth to you? I know mine is valuable!) with the sounds you want, the styles you want, and then get them all to 'play nice' with each other. If you have the time and skill to do that, you are good to go...

If not, caveat emptor...