Though it's not the answer your looking for, building a list will be a better long term investment. Even if you just create a free report and drive traffic to it that has to optin to download the report, you are building a targeted list that is opting in to your list and will be more receptive of your offers. A bought list will generally give you a lot of spam complaints, unsubscribes and very low open rate. Building a list is a much better ROI in my opinion. That's just my two cents because I hate to see people waste money buying a list when you can get so much more out of one you build yourself and establish a relationship with.