Money is tight for many people and those with disabilities often have tighter accounts than most. Gamers are not immune to this and as such Savy Gamer is a good place to watch for deals. The UK based site site is run by Lewie Procter. He monitors feeds and gets tips from a large number of on-line stores and retailers and forums and then reposts them on the site sorted by type of system.
These lists can be found on the site or more sensibly via RSS. The RSS feeds can be found here and cover Xbox 360, PS3, Wii, Wii-U, DS, 3DS, PSP, PS Vita, iPhone, PC, Mac, Linux, other and everything. Finally everything is posted to the @SavyGamer Twitter feed.
SavyGamer is not the most pretty site in the world, nor the most chatty but it does what it claims very very well. Subscribe to an RSS feed of your type of systems and you will get deals start coming in usually at the rate of a few a day but much faster during times such Steam sales.