Is this correct?

Hi,

I am not sure if sentences below make sense or if there is any mistakes, if there is, would you correct them into right ones?

- They are similar in frequencies. The Number of frequencies I ask somebody going abroad to buy is

similar to that I go to department stores for cosmetics. I don’t limit purchasing place to one.

I wanted to convey that the ratio of asking somebody to buy some comsmetics to going to department stores is similar.

thanks