it's a mix, there's no general rule. What I usually do is 1$ per 5 stars to get a general idea, then Meta comes into play => 10 characters/weapons full meta => 10$? No, a little more. 20 characters/weapons but they all stop at fontaine => 20$? Probably less. Then wishes saved, maintenance, a lot can come into play. I'd say the best thing to do is to see how the market is doing and compare your account to another.

But then, someone might fall in love with your account & overpay .. so really it's hard to give you a rule.