I found that fully closing schools works better than closing high-risk, and you can leave business fully open for significant periods. My best is 2,582 deaths at a cost of 385B. https://koronahra.cz/results/60e6550661cdc10019e509ce
Masks and max 10 stay on the whole time. I close unis at +100 infections, close all schools at +200, close high-risk at +400, and essentials only at +800. Ease up on the restrictions when infections go down. I ignored those breakpoints and left things as open as possible during the warm weather period, since you can safely do that as long as you kept the initial outbreak under control.
Edit: 2,112 deaths at 380B, just targeting +75/+150/+300/+600: https://koronahra.cz/results/60e65b5dfecc84001a33a3a3
Edit 2: 1,691 at 405B using the 2112 strat with slight adjustments based on intuition: https://koronahra.cz/results/60e65cc061cdc10019e509e6