seo expert looking for someone to promote my 4 software sites

hi looking for a cheap seo expert pref from india as not have much money in budget will be starting with $50 a month but will double this to $100 amonth if you can prove yourself with sales what i sell on these sites does sell but these are quite new sites i need proof of sites you have promoted and will need proof of linking promoting etc only for first month if you get no sales in first month then deals off but could be changed if you get keywords ranking good etc i know things take time but i have been scammed a few times so only looking for proven seo experts please pm if interested.