There is no "best" of anything. It's very subjective. The shirt that one person thinks is the best, another will think is not good enough or just not what they are looking for. You really need to get samples and try them out for yourself to see what is the "best" for you.
For ladies tees, try American Apparel, Alternative Apparel, Continental, Bella, Kavio, TQM Apparel. Also see these threads:
Best blanks for ladies' shirts have you got ideas of what kinds of shirt ladies like to buy
As for prices, you will need to get an account with each company to see the wholesale prices.