To complete this project, overtime is no sacrifice at all.
Tips
usage
在所不惜 always implies a cost (sacrifice, pain, money, time) that the speaker considers worth paying. It typically follows the thing being sacrificed or comes at the end of a sentence to emphasize resolve.
memory
Literally: even within (在所) that scope, I do not (不) begrudge (惜) it — i.e., no matter what it costs, I won't regret it.
