Both my leather leads were bought at local shows from a chap who makes them - £15 each. I started with a nylon lead like Jane suggests. At least with them you know what you are buying. The thing with leather that would make me a but nervous about buying mail order is finding one you like the feel of as leather can vary. Mine are lovely a soft and a delight to hold.
If you like Sandra - I would be happy to lend you my nylon and black leather lead as I don't show Jasper at the mo so am not using it. Then you can see for yourself which you prefer and also if you are going to take to showing or not - not everyone does
No-one will judge Inca any differently because he has a nylon rather than a leather lead - it's a question of which one you are better able to handle and are therefore more confident with as that is what will help show Inca the best.
Mail me privately if yu would like to borrow one or the other or both