Please do similar to what Polish based "Nuelink" did before: they been on appsumo for a long time and got very good reputation and made huge amount of money. And they always say "offer ending soon, buy now", then after some time they come back with increased price or additionally added tier for an extra price. I suggest you look into "Nuelink" strategy on appsumo and see how being on appsumo, being mentioned for being very useful, makes people talk about you and buy you and in future, when you stop selling ltd, people still be talking about you as an amazing software.