Surely to save the database a few thousand "Price in title" comments you could add some validation saying that if the deal isn't marked as a Freebie then there must be a dollar sign followed by an amount in the title.
I know that some deals have multiple deals and therefore prices, but at least one example could be in the title.
This was implemented many years ago. You'll get a warning if there isn't a price.
As other posters said, not all deals have prices (e.g. free games, % off at eBay) so making it a requirement would cause more issues.
I suppose it comes down to people flat out ignoring or not reading the messages.
It's also generally first time posters so they learn pretty quickly.