That's an excellent and practical question many buyers don't consider upfront. The good news is that for most benches, there are minimal mandatory ongoing costs, but smart maintenance does involve some optional investments for long-term preservation.
For daily upkeep, often just mild soap and water are perfectly sufficient. The primary potential "ongoing cost" depends heavily on your bench's material. Wood benches may periodically require a fresh coat of sealant, stain, or oil (every 1-2 years) to prevent weathering, which is a recommended purchase. Metal benches might need a specialized rust-inhibitor or touch-up paint if the powder coating chips. For synthetic materials like recycled plastic or vinyl, a dedicated plastic cleaner can restore luster but isn't strictly necessary.
You generally don't need expensive, proprietary cleaning solutions. A pH-neutral cleaner is a versatile and safe investment for most materials. The true "cost" is more often time and effort rather than recurring product purchases. To minimize costs, choose low-maintenance materials suited to your climate, perform regular gentle cleaning to prevent deep stains, and store or cover benches during harsh seasons if possible. Ultimately, a small investment in the right care products can significantly extend your bench's life and beauty, saving you money on premature replacement.