You don't tell them: give me what you value it for. You do your best to estimate what success will be (in value) to them. Then you negotiate from that.
If your best professional opinion is that the business is going to go under irrespective of your great work, then the ethical choices under the value model are:
1. Don't take the work at any price.
2. Do it for free.
Again, if a person has experience and great clients, the choice of pricing model is a problem. If a person lacks experience to judge what the value is in the client's domain and/or the client isn't proven to be good, pricing model doesn't matter as much.
The value model price isn't based on what the work is worth, it's based on what the freelancer believes the client believes the work is worth. Under the value based pricing model, if the client is deluded it's reasonable to fleece them...and deluded clients who pay well are good clients.
1. Don't take the work at any price.
2. Do it for free.
Again, if a person has experience and great clients, the choice of pricing model is a problem. If a person lacks experience to judge what the value is in the client's domain and/or the client isn't proven to be good, pricing model doesn't matter as much.
The value model price isn't based on what the work is worth, it's based on what the freelancer believes the client believes the work is worth. Under the value based pricing model, if the client is deluded it's reasonable to fleece them...and deluded clients who pay well are good clients.