I thought .294 and .295 were the best BAs, and the average has come in around there.
I wouldn't worry too much about how high or low your own BA/ERA is compared to the rest. A BA of .340 in this league would be disasterous; not enough players to choose from, and spending so much on BA alone that you don't have money for defence, power, walks, etc. I'd tentatively bet the correlation between BA and wins overall will be negative.