Why do we divide by two and multiply by two here? The comment above tells us that we do that, but maybe it's better to just turn minimum on into 250, maximum on into 1000 and same for minimum/maximum off (750 and 5000, respectively) and remove the multiplication / division here. IMHO it's counter-intuitive that i set a "minimum" value of 500 and then the real minimum turns out to be 250 (the settings can have a comment that says "these bounds are so far apart to take into account the user editing the defaults" or something).