I suppose it makes sense to have lite app (with unlockable content via IAP) and full paid app. I'm saying this basing on own experience of selling apps on the AppStore. If interested you may want to look at my post in our company blog about IAP vs paid app.
In App Purchase vs. Paid App | bees4honey blog
In two words - having lite version with IAP and paid version will increase a total revenue in comparison with having only lite with IAP or lite+paid.
