Merge pull request #14877 from Putnam3145/optimize-processing

inelastic exports no longer uselessly multiply their price by e^0 every tick

code/modules/cargo/exports.dm

@@ -84,17 +84,19 @@ Credit dupes that require a lot of manual work shouldn't be removed, unless they
 
 /datum/export/New()
 	..()
-	SSprocessing.processing += src
+	START_PROCESSING(SSprocessing, src)
 	init_cost = cost
 	export_types = typecacheof(export_types)
 	exclude_types = typecacheof(exclude_types)
 
 /datum/export/Destroy()
-	SSprocessing.processing -= src
+	STOP_PROCESSING(SSprocessing, src)
 	return ..()
 
 /datum/export/process()
-	..()
+	. = ..()
+	if(!k_elasticity)
+		return PROCESS_KILL
 	cost *= NUM_E**(k_elasticity * (1/30))
 	if(cost > init_cost)
 		cost = init_cost