The only way I can see to do what you are asking, is if the item is the lowest price item you sell, and you put a "run order" minimum on your payment methods for 1 penny above the price of that item, so they won't be able to check out unless they buy multiple of that item, or add something else to the cart. Really just establishing an order minimum for your store. Lots of places have them... even Temu won't let you check out unless you spend $10.
What you really want is to have a RUN if then condition on that item only, which isn't an option currently as far as I can see beyond the option I have suggested.
