I agree the hardware for computers can be more expensive, but if you play a lot of computer games a year like 30+ then you can end up saving a lot more cash to afford hardware upgrades for newer PC titles.
The games are usually cheaper for PC I notice especially if you buy games from Steam : http://store.steampowered.com/ , and even at electronics stores like Best Buy.
For example, the PS3 versions of Sims 3 cost 69.99 at my local Canadian Best buy : http://www.bestbuy.ca/en-CA/product/the-sims-3-playstation-3/10148155.aspx?path=b08d2f140de8361511675048cbdd3765en02
while
the PC and Mac version of Sims 3 cost 39.99 : http://www.bestbuy.ca/en-CA/product/the-sims-3-pc-mac/10124228.aspx?path=37a7f82fb170e18f537eca4d0ff3369cen02
source:: http://www.bestbuy.ca/Search/SearchResults.aspx?path=ca77b9b4beca91fe414314b86bb581f8en20&pcname=MCCPCatalog&q=sims%203&sp=BBY_en-CA_Site-WideSP&Category=Entire%20Site
If you play buy 24+ PC games a year or 2 PC games a month from online and offline stores, you can save up to $ 720+ dollars = 24 x 30 dollar average discount on some games which is enough to pay for a new PC or better parts to upgrade your PC.
Onlive is also available on the PC which lets you play PC games on the internet as a purchase or subscription/rental service. I heard the system requirements for OnLive are low since the games are run off of OnLive's servers and streamed to your PC via the internet.