3D artist here!
If I were you I’d try looking at models for references instead of for direct use. Models aren’t cheap, and the more detail something needs/has the more expensive it’s going to be.
The image in your example would be fairly easy to model since it’s doesn't require much detail, is an exterior, and is in the distance. It’s also not textured. For something like that I’d probably charge ~$75, but other artists have different pricing depending on experience and what programs they use.
Interiors are expensive. A good palace interior render (one room) could easily cost hundreds of dollars.
Another option is to look at photogrammetry models for reference.