Yes, I think there is something that you are missing...  your wife put the information into the calculator wrong, and you got the wrong answer....There is an old sayings about computers (and calculators)... Garbage In, Garbage Out.

Try this....  2 loads,  17 items on each load.  Each item is worth $25.

17x25+17x25 = 

See what answer you get with that equation.

What this says is the first load has a value of 17x25, and the second load has a value of 17x25.  Add those two together and you get the combined(total) value for both loads.

17x25+17x25 is NOT the same as saying 17+17x25.   I think you are finding that out.