How to decide proper pricing?

I'd say avoid cheapest. If your key selling point is cheapest then you're on a race to the bottom with shrinking profit margins. Worse, you get stuck there because you don't have the cash to build a premium product and reposition yourself.

I voted for the last one. Start with a price you think is "ok", don't overthink it. Once you have some regular sales, try to double it and see what happens. If the sales don't drop, do it again, and again. Until sales drop by 30%. Pricing is super hard to find and that's also the easier leverage we have, so let's play with it. TL;DR: charge more!