John decides to trade in his stereo system.  His old system cost 250 dollars and he got 80% of the value for it.  He then buys a system that costs $600 that he gets a 25% discount on.  How much money came out of his pocket?
He got 250*.8=$
<gadget id="calculator">250*.8</gadget>
<output>200</output>
200.
He gets a 600*.25=$
<gadget id="calculator">600*.25</gadget>
<output>150</output>
150 discount on the second system.
So it cost 600-150=$
<gadget id="calculator">600-150</gadget>
<output>450</output>
450.
So he was 450-200=$
<gadget id="calculator">450-200</gadget>
<output>250</output>
250 out of pocket.

<result>250</result>