Buy every step down from MA

Hi, I need signals with following condition:


the are levels
step is the int measure betw levels:

step=10;

1 level = MA+10
0 level = MA
-1 level = MA-10
-2 level =MA-10*2

if Close<MA, buy 1Size every Level down from MA
if Close>MA, sell 1Size every Level up from MA

Code:
Step=10;
buy = Cross( MA-Step, C);
1. I have a feeling that something wrong is here.
2. And how to connect these guys?

1st buy at -1 Level: at price EntryPrice =(MA-1*Step),
2nd buy at -2 Level at previous EntryPrice minus step: EntryPrice = EntryPrice -Step



thank you