I am looking at a stock which is currently trading at Rs.1400 and I am looking to go long when the stock falls to Rs.1300. I am planning to buy 500 shares. On the other hand, I am not sure if it will fall to such levels. 

My question is - Would it be wise to accumulate 50 shares every time the price dips, so that I can aim at an average price of Rs.1300? Or should I wait for it to fall to Rs.1300 and accumulate all the 500 shares at once. 

What are the advantages/disadvantages of both these approaches and which one makes more sense?