How Much Would You Pay for a Skeleton Key?

So I see a lot of people complaining about the number of chest drops vs item drops in games. I'm sure Valve makes pretty good money selling keys of different types for different chests.

My question is, how much would you be willing to pay for a permanent / semi-permanent skeleton key? $60? $100? Perhaps the most realistic idea would be $20-$30 per month for a skeleton key that would open every chest that dropped for you for 30 days.

I think it would make sense for Valve to sell an item like this. They wouldn't necessarily lose all that much money over selling a dozen $3 keys per month, and I'm sure some players who don't bother to buy individual keys right now would pay $30 for a key that would open every chest they have right now and every chest that drops for the next month.

I think the skelleton key should have a 99(or whatever number, I just came up with this one cause I play The binding of Isaac and there is a Skeleton Key there that gives you 99 keys) usage term, not open every chest you have for 30 days.People would just buy chests and open them.Having a limit would ensure that it's not abused.

Bear in mind that chest prices on the marketplace would be adjusted accordingly.

Currently you can pick up chests for £0.03 each, but that wouldn't be the case if there was such a thing as a 'Skeleton Key' for unlimited use.

Maybe it could only work on dropped chests, and not on purchased chests. Or make the purchased chests more expensive, as another already mentioned.

It would have way too big of an impact to the trading community, if anything they could sell a bunch of keys at a discount?

I would like some hero-specific chests though, haven't been any in a while and I have some treasure keys lying around.