That's a fantastic and very practical question. Having consulted on several municipal projects, I can tell you the "most cost-effective yet durable" option isn't a single product, but a strategic combination tailored to different urban zones. The goal is to maximize lifespan and minimize total cost of ownership, which includes purchase price, installation, maintenance, and collection labor.
For high-traffic downtown cores and transit hubs, powder-coated stainless steel bins are the undisputed champion for durability. While the upfront cost is higher, they resist corrosion, graffiti (if treated with a proper coating), and vandalism far better than other materials. They can last 15-20 years with minimal repair. Look for welded seams, heavy-gauge steel, and tamper-proof hardware.
In parks, residential streets, and lower-vandalism areas, rotationally molded polyethylene (heavy-duty plastic) bins offer excellent cost-effectiveness. They are immune to rust, are quieter, and come in various colors for waste stream segregation (trash vs. recycling). The key is thickness; aim for a high-density, UV-stabilized resin. These can easily last 10+ years.
The real game-changer for cost-effectiveness is standardization. Choosing 2-3 standardized bin sizes and styles across your city drastically reduces costs for replacement parts, liners, and collection truck compatibility. It also simplifies maintenance crew training.
Finally, consider a phased integration of "smart" bins with solar compactors in overflowing problem spots. While a larger investment, they reduce collection frequency (saving on labor and fuel) and provide data to optimize routes. They are not for everywhere, but strategically placed, they pay for themselves.
So, the most effective program uses stainless steel for high-abuse zones, heavy-duty plastic for general use, all built on a policy of standardization, with a pilot of smart compaction in key areas. This layered approach spreads the budget while building a system that lasts.