It depends on what you are looking for. Are you looking for a simple cable cord, DVD player, vcr, blu-ray player, etc.? The least expensive one from above would be a cable cord, but these other accessories can be cheap as well.
The least expensive brands for HD televisions are the 'off brands', such as Akai. While these brands work perfectly well, they often do not have all the feature of mainstream brands.
You can buy discounted Prjection tv accessories at your local Wal Mart or Target. Check their ads for sales. You can also find sales on tv accessories by visiting; http://www.amazon.com/TV-Accessories-Audio-Video-Supplies/b?ie=UTF8&node=172664
some accessories for a 3d tv would be 3d glasses with an emitter, a 3d adapter, a remote, and HDMI cables. You can often find these accessories in a kit made specifically to go with 3d tvs.
The lowest priced nationwide bundle that is offered $19 a month. It includes TV, internet and phone.
The variety of places to purchase television accessories is rivaled only by the number of accessories available to purchase. Remote controls, cabling and the like can be purchased at mass merchandisers like WalMart, big box electronics stores like Best Buy, online, and even in grocery stores.
Satellite Super Store and World of Accessories both have add on accessories for Sky TV subscribers. The Sky TV website has it's own online store as well as a retail store locator where items can be purchased.
Yes, they do have brackets and things to hang the televisions on the walls. http://www.usa.philips.com/c/tv-and-monitor-accessories/fixed-sqm6375_27/prd/
TV mounts, stands, anti glare products, different kinds of remotes, and entertainment stands are just a few examples of TV accessories you can get in today's market.
http://www.sony.co.uk/product/acc-television-and-projector-accessories you will find most of what you are looking for there or you could also visit your local tv and hardwware store
Wall mart does sell television accessories, from cords to cables and even some places will fix your television sets. for cheap prices and good quality work
HDMI accessories for a 3D TV ca be purchased at several department stores or can be purchased online through sites such as Amazon. Department stores that sell 3D TV's such as Sears or Best Buy also sell HDMI accessories for use with the 3D TV.
This changes from time to time. However, currently, the absolute cheapest stripped-down package I can find at the moment is offered by DirecTV.