I agree that you should probably just try to pray assuming you're at the correct alignment. I think the problem is basically this: Prayer costs increase based on the number of times you've done it, but they change for each specific prayer type. Crowning and precrown are different kinds of prayers, but the levels change based on the number of precrowns you've got. So, for example (made up numbers)
0 precrowns
Very close = 10000
Favours = 20000
Extremely favours = 25000
Precrown = 30000
Crown = 30000
1 Precrown
Very close = 10000
Favours = 30000
Extremely favours = 40000
Precrown = 50000
Crown = 30000
2 Precrown
Very close = 20000
Favours = 50000
Extremely favours = 80000
Precrown = 100000
Crown = 30000
So even though you're seeing "Very close" you still have enough piety to crown.
Hoping to win with every class, doomed. Archer, Barbarian, Bard, Beastfighter, Druid, Elementalist, Farmer, Fighter, Monk, and ULE Priest down.