Ignore sunk costs: One of the most popular book Kickstarters ever was a project to publish a new, attractive version of the Bible. It raised more than $1.2 million. In this video, released shortly after the books were finally printed, we learn a lot about sunk costs. The first: It’s a fallacy to decide that merely because more people are buying something that it’s now a more important project. The joy you will create per person doesn't change when you have more readers.
Not only that, but given the efficient nature of book printing, more books printed shouldn’t lead to a two-year delay in the project.
Second, and far more useful, is understanding that real artists ship. In this case, the creator of the project spent every penny available to overengineer and procrastinate. My guess is that he would have gone right to the limit with $500,000 and with $5,000,000. The amount of money you have to spend should have nothing to do with how you spend it. Worth re-reading that sentence. Budgets exist to help us make plans, not because the problem we seek to solve is related to the money. It's not. It's related to the expectation of our customer.
Once the theater is big enough that you can't see the folks in the back row, it doesn't matter how big the theater is.
In this case, as in so many others, the real question is: What is it for?
What is the project for? What did the backers buy? When is it time to ship?
When making decisions, we need to drop much of the traditional narrative and get back to a very simple analysis:
At this fork in the road, what are our options?
Given the promise we've made and the resources we have to keep that promise, what's the best option?
Do it regardless of how much it cost to get here, regardless of how nervous you are, regardless of how hard you worked on the other option. Those aren't factors in making a rational decision.