I congratulate you on your decision to accept Bitcoin as a means of payment, because it is desirable for every business to have as many payment options as possible, which means that you have a greater chance that the customer will decide to come to your store. I would suggest one more, in my opinion, very smart business decision if you can afford it considering your costs - and that is to enable an additional discount (perhaps 5-10%) for those who pay in Bitcoin, and this can motivate some potential customers to decide on that method of payment.

As for what would be best in relation to whether you want to save part of the profit in Bitcoin, I think that as a business person you always need liquidity, but you could invest a part of each sale in Bitcoin as a long-term investment. It doesn't have to be a lot, maybe 10-20% if you think it can help you in the future.

In order to attract more customers, perhaps you should invest in additional advertising, whether it is paid advertisements on the radio station, or smaller billboards in front of the store.