A good early solution is to have your mall use storage chests and set filters to control what will be stored in them. Then your input inserters can be set to only add the materials into assembly machine if there are not enough of that item in the network. Bots will store stuff in filtered storage chests before adding to unfiltered. Easiest recycling system. For instance, if you have a storage chest filtered for yellow belts that your yellow belt assembler drops them into and your red belt assembler pulls them from then as your bots upgrade your belts from yellow to red they will deposit the belts they pick up into that chest and they will be used to make more red belts. Then if the inserters adding gears and plates to the yellow belt assebler see there's enough belts in the network (because your construction bots just dropped off a bunch of belts after uograding) they just wont feed the yellow belt assembler.
There is a setting called expensive recipes that makes things more expensive, the landfill could be changed for expansion or you could have the expensive recipes setting turned on :p worth checking at least.
In space age it's a setting called technology multiplier which is set as standard to 1, and checked the 1st stream where zed showed the settings he's using and it was not touched so assumed it's a space age setting
