What price for a wallpaper?

Hi,

I plan to create nice wallpapers and then sell them on my website but I would like to know your opinion about this. At what prices can I sell HD wallpapers? And what is the best resolutions for me to create wallpapers?

Please help.

I didn't find the right solution from the Internet.

References:
http://www.graphicdesignforums.co.uk/threads/what-price-for-a-wallpaper.24985/
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Thanks