Help me with Marketing - Repost -- 3

I have a website design company that specializes in Joomla! websites. I also a huge email list (540,000) that signed up for this list. I want to build my clientele and expand my business. I've build over 100 websites, and I currently have 18 open and active accounts with my hosting company. I do not know what the best way to expand my company is (email campaign or another venue) but I am willing to work with the right person to accomplish my goal of 50,000 new builds in the year of 2015. To start, my budget is low, but I will be able to higher it as I get a few extra clients. I plan on selling my services between $499-$1499. Will discuss that when I hire after hearing what you have to say.