Hamza is interested in making and selling fresh Chelsea buns close to Stanmer park. He is a risk seeker and an optimist who believes that it will always be a good business day. Historical information on sales demand as received from other bakeries close by reveal that Hamza can sell $80$ chelsea buns on a good day, $50$ chelsea buns on a moderately successful day and $8$ chelsea buns on a bad day. Cost of making each Chelsea bun is $1\mathrm{.}39$ and the selling price per unit is $3\mathrm{.}03.$ Chelsea buns not sold at the end of the day will be taken to the local food bank at no cost$.$ What would be the net margin on a bad day for Hamza?

Round your answer to $2$ decimal places. e$.$g$.10\mathrm{.}43$