That's up to you and how much you want to ensure that you want to make money. Relying on a product that is no longer being developed is foolish at best and is pretty much asking for trouble.Sorry, I'm confused. How many options are you suggesting I should ensure I have, and how can I determine which of those will last longer than the current solution I'm using....therefore being worth the investment of my time and money?
ETA: At least you should be making sure that the vendor that you use is still around and willing to update the product you are using. It's called having a backup in case things change.
ETA2: And I largely don't think it should be treated as a "cross that bridge when we get there" sort of thing either. You should be proactive so that when things like this do happen, you can adapt much faster. It's never a good idea to assume that things will always work the same way tomorrow as they do today.