Cartomizers are made to be disposible, and thats why their cheap. If you compare it to cigs, your def getting your moneys worth. A 5-pack of cartos is about the same price as a pack of cigs. If you can get one week out of a single carto, then that means a 5-pack will last over a month. If you smoked a pack-a-day of cigs, then you paid the price of a 5-pack of cartos EVERYDAY, compared to every MONTH when you vape.
You can clean cartos, but personally I think its not worth the hassle at all. I get on avg 1-3 weeks from one carto so Im hands down getting my moneys worth. And most cartos dont work as well after theyve been cleaned, so to me its just not worth it.
Using a carto tank generally makes the cartos last even longer.