I've been following Canon's instant rebates for the past couple of months.
They included the A2200 ($10), ELPH 100/300/500 ($20), SX230 ($20) and SX30 ($30).
The original rebate was extended to be valid until July 31st.
Now that it expired, Canon issued a new rebate (valid through August 20th),
including only the A2200, ELPH 100 and SX30, with the same discount amounts.
However, the rest of the cameras, now excluded from the new rebate program,
actually have lower prices than when they were on the rebate program!
The SX230 and ELPH 300 are both $50 off and the ELPH 500 is $30 off.
Seems like the rebate program is also a way to control street prices by Canon.
I know this is not the first time someone raises this claim, but I happened to see the prices fluctuate myself.
Bottom line - The ELPH 300 is now $199 and the SX230 is $299 - try to get a refund if you bought them recently.