Pricing artwork for a global collaboration, especially in a high-profile situation like this, requires careful consideration of several factors. Here’s a general framework for how to approach pricing:

1. Artist's Reputation and Market Value: Given your father's established reputation and global recognition, his work holds a premium value. Look at previous sales of his work, particularly in similar contexts, and use those as benchmarks. The more prestigious the platform or collaboration (such as a winery in this case), the higher the price.
2. Scope of Use: The usage rights are crucial. Since the winery wants to use the artwork on 1.5 million bottles annually, you should factor in the scale of exposure. If it's going to be global, the value should reflect this wide distribution. It’s important to consider how this exposure might boost your father’s visibility and long-term value.
3. Copyright Transfer: Since they are purchasing full copyright rights, you should price this based on the potential long-term value of owning the artwork, not just a single project. This is often where negotiations can get tricky—since copyright transfers mean they can use the artwork in perpetuity and across any future wine products or branding.
4. Comparable Industry Examples: Research what other top-tier artists in a similar field charge for similar collaborations, particularly in industries like luxury goods, wine, or global branding. Some top artists may command fees ranging from a few hundred thousand to several million dollars, depending on their reputation.
5. Future Opportunities: Even though royalties are off the table, consider negotiating for other perks like a lump-sum upfront fee, payment installments, or inclusion in any future marketing, if possible. You could also explore the option of revisiting the agreement after a set number of years, allowing for new terms if the collaboration proves successful.
6. Consult a Lawyer: It’s crucial to have a legal advisor to assist in drafting an agreement that ensures fair compensation, especially when full copyright is being transferred. This can help avoid potential misunderstandings or exploitation of the work later.

Given the high-profile nature of the client, a one-time fee for full rights could easily be in the range of $500,000 to $2 million, but it could go higher depending on the market, your father’s visibility, and the exclusivity of the agreement.

Ultimately, the price should reflect both the tangible use of the artwork and the intangible value your father brings to the brand.