My advice:

Avoid trying to make a hand-crafted sporran too flashy- i.e. contrasting leathers, fur/hair, tooled leather, etc. All this tends to make such sporrans look like a Boy Scout craft project rather than a proper sporran. if you really want to find a niche market, make something similar to current sporrans, but make it in much, much better quality.

For example, consider Lamar Britt's sporrans:
http://giftshop.scottishtartans.org/sporran_fb.html

and sporrans by McRostie Leather:
https://www.said.net/secure/mcrostie/index-shop.asp

Excellent materials and superb craftsmanship beat "funky" designs IMHO.

Cordially,

David