Sarah, you would be better off geting a soil test done before applying limestone. If your soil is already on the alkaline side, you would be making it worse applying lime. A soil test, which is usually very inexpensive, will give you a wealth of information about the pH and nutrient levels in your soil.
This common misconception that BER is related to calcium levels in the soil has to be cleared up. The latest research has proven that this is most often not the case. 99% of the time there is MORE than enough Ca in the soil to fill the
plant's needs. It's most often caused by either too little or too much water, both of which will cause the
plant to be unable to absorb enough calcium from the soil to keep up with the
plant's growth needs. The
plant then starts translocating it, pulling it away from the fruits causing BER.
Oh, and btw, paste varities are more prone to BER than others. I don't know why this is though.