refurbishedcontainer.com
Someone searching the singular is usually looking to buy one specific unit, which makes this form the better fit for a product page, a dealer, or a conversion business.
Used shipping containers trade in volume as storage, site accommodation, workshops and building components, with the refurbished segment adding repair, painting and modification between the shipping trade and the end user.
Container conversion moved from novelty to an accepted building method with planning precedent, which widened the buyer pool considerably.
The name suits a dealer, a conversion business, a modular construction company, or a marketplace. It also works as a companion to the plural for anyone wanting both.
Two plain words, no hyphen, .com, and exactly what a buyer types. High ticket value plus research-led purchasing is where an exact-match category domain pays for itself.
Offers considered.