China bought 45% of AKPO for $2.5B in 2006 when oil was $60.
China is growing at 8-10%, oil is at $75. In 7 years China's economy will be double what it is now.
I think we can at least double what they paid for AKPO, so the answer to your question... $10 per barrel. One billion barrels of proven undeveloped is worth $10B dollars.
The info that ERHE has an AKPO type field is also very inaccurate and misleading. These fields and prospects are not connected. ERHE likely has 5 Akpo type fields which is what I have been saying all along. AKPO is not a gas discovery. It is a gas, oil condensate discovery. Whether any of them are bigger or smaller than AKPO can not be determined by a single well in any given prospect. Each will stand on its own.