Comment by rmunn

I'll note that sunken cost is not always a fallacy, or perhaps I should phrase that as "things that look like the sunken cost fallacy aren't always that fallacy". In your specific case, for example, you didn't feel like starting from scratch, because that would involve paying a cost (in terms of time learning a new system) that you didn't want to pay. So it's not actually "I sunk so much time into this, I want to get my money's worth" as it is "cost of learning something new: high. Cost of sticking with what I know: zero." So not exactly the same as the sunk-cost fallacy.