Actual cost = main cost+other costs = 3.75 ÷ (1-40%)+2.30 = 6.25+2.30 = 8.55,

That is, the actual cost of a box of hawthorn (half a catty), its main cost is 6.25 yuan for hawthorn (including 40% loss cost), and other costs are 2.30 yuan, totaling 8.55 yuan.