Sometimes I have to discuss with my customers about the price of a HP41CL assembled - it is far too high for them. And it is expensive, yes; but for a reason.
I have bought 4 calculators during the last 4 weeks - and one of them doesn’t work properly, and another works but cannot be sold due to cosmetics. So, that’s 50% failure rate!
It doesn’t have to be that bad - but, on average, I can sell just 2/3rds of what I buy - provided that I do the repairs perfectly and without damage to any parts.
And when you get a bad battery bay, you know that it can be repaired, but a user of an HP41CL expects an original, rust free battery bay - that has to come from yet another calculator!