Consultant for hire - will work for beer!

Adding consultants to NIH projects can often be a confusing task, and can require some awkward conversations with your collaborators. One important item to note is that consultants can be paid whatever is considered "reasonable".  In other words, don't hire someone for what amounts to 5 hours of data review for $20,000, but work out a cost estimate that fits into your budget and is acceptable to the person.  I have seen arrangements where consultants were paid a few thousand dollars plus travel costs, and others where consultants agreed to work for free.  One consultant even agreed to work for free as long as when he came to town for the grant's yearly meetings, his tequila was on the PI's tab. Talk to your collaborators and see what they are comfortable with, and don't be afraid to ask them to work for lower pay if your budget is tight.  Throw in washing their car and you might just have yourself a deal...