Making your commission private: +50% extra
Drawing OC without ref sheet + 20% extra
Also if you don't sure if your idea commission suitable for me ---> check out my DON'T DRAW LIST
Here some more examples:
Sketches:
https://www.furaffinity.net/view/45157784/ (SFW)
https://www.furaffinity.net/view/45181084 (NSFW)
Line art:
https://www.furaffinity.net/view/44486179/ (SFW)
https://www.furaffinity.net/view/43685165/ (NSFW)
Full shading:
https://www.furaffinity.net/view/44877624/ (NSFW)
https://www.furaffinity.net/view/40802532/ (NSFW)
https://www.furaffinity.net/view/44121827/ (SFW)

Examples of DIFFICULT OC DESIGN\CLOTHES
OC design: https://www.furaffinity.net/view/36368120/ and https://www.furaffinity.net/view/44633591/ (including wings, extra limbs\heads)
Clothes: https://www.furaffinity.net/view/42233203 (a lot buckles, belts, layers of clothes, accessories, armor, swords)

BG examples: (price depends of perspective and detailes number)
https://www.furaffinity.net/view/42078330/ - simple for free
https://www.furaffinity.net/view/40828945/ - simple for free
https://www.furaffinity.net/view/40052328/ - medium
https://www.furaffinity.net/view/39487116/ - medium
https://www.furaffinity.net/view/38163695/ - medium
https://www.furaffinity.net/view/43292946/ - difficult
https://www.furaffinity.net/view/44486179/ - difficult
https://www.furaffinity.net/view/43807038/ - difficult (NSFW)