What should I check and think about before purchase?
You should check out the demos in here, because what you can see in there is what you can do with our menu. Except in WordPress there isn't a menu icon giving option, but you could make it happen like this. Also if you are using WordPress, try out the trial version, what you can download from here, it has every option, what you can do with the full version, just the full version has more themes.
What you should really consider before purchase is, that for how long would you like to use the Accordion Menu, not because of the usage period, but because new Joomla/WordPress and PHP versions will come out, and the codes used today will be changed in them, and we need to change our code too to adjust to them, so to have a properly working menu, you will need an updated version after a while.
Support doesn't cover customizations, only purchase our menu, if you want to use the existing features. Usually the questionable parts are, which menuitem can be active and opened, so check out those. Also under the Menu Types title in our documentation that menu type, which you will want to use, to see it's settings.