My thesis is that when you compare the two....the algae infrastructure will be somewhat but not prohibitively greater than the already existing petroleum infrastructure.

How about if you compare it to infrastructure cost including ecological costs that will be necessary to extract liquid fuels from say Canadian tar sands. Is there a point at which conventional oil extraction costs becomes more expensive than production from renewable substitutes such as algae?

Another man after my own twisted heart!!! Hear, hear!!!!

Total agreement!!!!!