A littele advice ?

I'm Interested in making and website which will promote my applications for android mobile devices. But in the website I want to make a place where everybody can sell their applications like here market.android.com. What CMS is good to use? How much host should I use ? Other thinks I have to pay ?

too expensive to build such market place - it could cost you anywhere from $4000 t0 $8000

may be use some themeforest clone.

Also you would need dedicated server at least to run such thing