Why not consider creating ebooks specifically for the reprint rights buyers. It's a big market and there's constant demand for new products to sell.
I agree with Eva on this unless you include restrictions with your rights people will be offering you ebook on ebay along with 300 other titles for $1.95 within weeks.
The funny thing is the people doing this aren't the ones making the real money - the authors that are aware that this will happen are :-)
If you're going to offer rights then make sure you have a nice backend sales plan - affiliate links in the book - promotions of your other books etc.
If you do this you'll look forward to seeing everyone buying you book for pennies - because you know it'll come back to you in affiliate cheques and backend orders.
Having hundreds/thousands of people selling your books in this way is like having an affiliate army on steroids.
Here's a great example of a book I launched a few days ago: http://www.infoclicks.co.uk/traffic/
You'll see both the initial upsell (extra books and software) and the secondary upsell the "Resell Rights" after you click on the order link.
Now this is important:
I want the resellers that buy my books to also make a lot of money - the more profit they make from sales of my books and I have increased the chance of them buying from me again.
I also create a ready made web site and include themed bonuses too because it adds value to the package and makes the reseller's job easier.
Look at it this way - Would you rather sell a hundred of you books at $25 each and get all of your backend sales from just those hundred people.
Would you rather sell a hundred reprint licences at $100 each and see potentially thousands of people buying from your backend links as your book is resold and resold.
Every book your customers sell leads to more profits for you down the line.
To help your resellers consider these restrictions:
Cannot be offered from a membership site
Cannot be offered free
Cannot be offered as a bonus
Cannot be bundled / Must be sold as a standalone item
By law you cannot enforce a minimum selling price but make sure you offer a suggested one.
Also consider if you want to offer Master Rights or simple Reprint Rights.