4.99$ or 9.99$ one time fee or 1.99$ a year feels about right for me. I would prefer the one time fee because I don't expect it getting regular updates(I'm fine with paying again for large version updates. I'm already paying for iStat Menus, Affinity Designer, BetterTouchTools and they all work with this business model). It is a utility that I would use every now and then, so subscription feels wrong.