The up-front numbers overlap
A basic cream-finish satin polish on a good slab sits at the bottom of the polished range and undercuts almost any coating. A full aggregate exposure at high gloss on a slab needing significant patching sits at the top and costs more than a flake epoxy floor. Comparing the categories in the abstract is less useful than comparing two quotes on your actual slab.
Where the twenty-year gap opens
Polished concrete needs a burnish and re-guard visit every five to ten years in heavy traffic, done in a single visit at a fraction of a re-coat. An epoxy floor eventually needs its topcoat renewed, which is a closure, a light abrasion pass and two coats. Over two decades in a commercial space that difference is substantial.
The slab decides more than the budget
Polishing exposes everything the slab has been through, trench patches, adhesive residue, an inconsistent pour. Coating covers all of it. On a damaged slab, polishing is not the cheaper option because achieving an acceptable result costs more than simply coating over the history.
The middle option nobody mentions
Grind and seal, grinding the slab then applying a penetrating or thin topical sealer, costs less than both and looks similar to a low-gloss polish for a few years. It is honest value in a garage or shop. It does not have the depth or lifespan of true mechanical polishing and should not be sold as polished concrete.
Want this answered for your slab?
Free site visit with a moisture reading, then a written fixed price. Across the BC Interior.