Well because most of the data needs to be referenced in my case I force users to include a link to their source helping minimize time spent. Data accuracy is essential on my site though and without it my site would just be another unreliable source on the web.

I haven't completely opened my website so I can't say how big of an effort it will require in the future. But I plan on possibly using Mechanical Turk or some other similar source paying penny's for accuracy verification.

I'm interested to know what your working on. Do you have an email address I can contact you at?