Okay. Well I'm going to base my answer here off of your past answer of 3 lb of onion and 5lb of pork. If your answer is wrong then mine will be too, so make sure to double check yours!
Exact solution: (3lb x $2.99) = $8.97 for the onions and (5lb x $5.49) = $27.45 for the pork. Altogether it is $36.42.
Estimated solution: (3lb x $3) = $9 for the onions and (5lb x 5) = $25 for the pork. Altogether it is $34.