CSGO betting website Develpment

i am working on a website that incorporates the functions of a few different sites all in one place. I wanted to get some feed back from you as far as what you think about my idea and what the cost would be. Here is a few of the sites that im basing the ideas for my site for, first [login to view URL] its a site where you can bet skins. you log into your [login to view URL] to deposit skins for "gambling" from your inventory. so im going to need that done. make it so that people can log in to there profile from there steam account on my site. next there is [login to view URL] witch is the same type of deal. you log in with your steam account and you are able to post bets on pro counter strike global offence matches by betting your skins or guns. also this site has an available column where you can post your items up for trade for items that you would like in return so i would like that incorporated in my site to. and last but not least there is [login to view URL] where you can deposit skins and sell them for real money instead of selling it on the steam market and only being able to use that money within the [login to view URL] market place. the way it works is you buy coins and pay for the items in coins and after that you can redeem your coins for cash in return. as you can see i really just want a one stop shop. a place where you can do it all. if you are interested please look into all the sites and dig into them a bit and let me know what you think.