RLV News is skeptical about the size of the prize described by this New Scientist article:
The challenge: put a tiny satellite that weighs less than 19.99 grams - the weight of about two British pound coins or four US quarters - into orbit on a budget of only 999.99 pounds (about $2000). The satellite must complete nine orbits around the Earth, and this must somehow be verifiable from the ground.
The prize: 9,999.99 pounds (about $20,000).
Here's the official site. Instead of the N-Prize of 9,999.99 pounds for the basic case, there's an "N-Plus" prize for 10.000.00 pounds (that's, if I did my financial math right, uh, still about $20,000) if part of the satellite is also brought back to Earth.
For perspective, the CATS (Cheap Access to Space) Prize was for $250,000 for a 2kg payload that reached 200 km or higher using private industry.