Stretch marks....? Baby number 2

Sarah • Married 4/7/14 little boy age 2.5years and expecting 2nd baby in April 2015 ❤️
I have quite a few stretch marks from my first baby... Hope this doesn't sound too silly but if I have them already is it really worth spending all this money on creams lotions and potions to help prevent them? 
​I bought everything last time and I religiously rubbed on my tummy twice a day and still got them anyway....? 
​Thoughts please 
​Thankyou :)