#define SET_PRICETYPE 151
uint g_PriceType = 0;
...
in the main switch/case:
case SET_PRICETYPE:
g_PriceType = (int)arr[1];
arr[0] = 1; break;
...
and then:
#define Bid (::SymbolInfoDouble(_Symbol,g_PriceType == 2? ::SYMBOL_LAST : ::SYMBOL_BID))
etc.