when do we get profits(making money)?

when we sell high or sell alot(small profits =$3)

the reason im asking is because i think im stuck..

i sell alot but i see my profits go away fast when buying inventory again!

i dont know if im crazy on rebuying merchendise again eveytime i have 2 pcs left or simply my profit of $5 and less is not good enough.

please tell me your experience on what am i doing wrong!

-my business is a retail/wholesale store.

please any knowledge will help as i feel upset

thank you.

im not doing good in my business,

just need your advise