This Tools model - Door Key - is ready to drop into a scene as-is, and sells for $19 on TurboSquid. Budget for 3,765 polygons and 3,754 vertices when you plan the scene. What matters is not the number itself but how many copies of the object your scene has to carry at once.
The material set is 3 maps, painted at 4096 x 4096. The mesh is modelled at true scale with quad-dominant flow, so subdivision behaves and the object does not need rescaling on import. Objects are grouped and named logically, so isolating a single part for a material change is a two-second job rather than a cleanup task.
On this listing the stated applications are technical visualization, architectural visualization and product rendering. It went on sale in 2017 and has been kept in the catalog ever since. It works as a game prop, a film and TV set element, or a reference object in training material.
Questions About This Model
How heavy is the Door Key mesh?
3,765 polygons and 3,754 vertices, built as polygonal quads/tris. What matters is not the number itself but how many copies of the object your scene has to carry at once.
Can the Door Key model be modified after purchase?
Yes, modification is covered by the license. Most buyers adjust materials or decimate the mesh for their engine; only redistribution of the source file is off-limits.
How much does the Door Key 3D model cost?
It is listed at $19 USD on TurboSquid. That is a one-off purchase under the Royalty Free license - there is no subscription and no per-project fee afterwards.
Does the Door Key model include materials and textures?
The product page states what ships with each format. Textures, when present, come inside the download rather than as a separate purchase. See the listing for the exact contents.