Try this:
IF(TOTAL_PRICE:SUM = 0,NULL,IF(TOTAL_PRICE:SUM > 0,RowCount,TOTAL_PRICE:SUM))
Let me know if it is helpful..
Explanation:
Basic syantx for ifan If condition is:
if(condition,true,false)
You're using ifan If statement within ifan If statement. so the synatx would be like this:
if(condition,true,(if criteria does not match then u are checking another if condition) if(condition),true,false)
in uryour formula, if you can see if the total sum is not zero then ypouyou are trying to return Total priuceprice value then you are again checking ifthe If condition which is syantaticallysyntactically incorrect