When you see a rumour end with the word "considering", it's always wise to tread cautiously. Because that word could mean anything. That said, this particular PS4 rumour comes from Britain's The Times, so it's at least worth... consideration.
The report says that Sony is looking at "pricing the new device at about £300", which is over £100 cheaper than the PS3 was at launch. I won't convert the currency, since that's a meaningless gesture, but it doesn't take a mathematician to know that's a reduction of over 25%.
The PS3 launched at $599, so apply the same rate to the US—yes, we're getting our feet off the ground by this stage—and you're looking at a possible PS4 launch price of around $449.
Then again, seeing as the report says Sony is simply "considering" that pricepoint, maybe it'll be $1000! Maybe it'll be $1! We don't really know, and chances are, we won't know on Wednesday, either.
Sony upgrade cheaper than predecessor [The Times]