like after a few seconds or minute you get the item or the thing completes itself
or like
on build it checks that if you have the amount of money or something is in your inventory that is required by the building then place the building site that requires nothing to make except the hit of hammer and if you dont have the money it either doesnt place the building site or place it and if you dont have the money then destroy it
Easy way:
for the second one if dont care to read
if values are true then place the building site or else destroy it when its placed or skipevent