Depends where you're located. I've liked Holben's lately for mid to low-tier pricing and good quality. The "Bay" can be good value buying too--- some sellers specialize in straps. Start with the type of leather you're interested in and go from there.
What kind of strap design do you prefer? Racing, rally, distressed suede, stitched leather? There are so many styles, and so many artisans producing them, it helps to have a direction before making a recommendation
Thank you all. Apologies for being vague,new to this area. I would like to purchase a padded strap,preferably with deployment. As a very new seamaster owner (last Thursday) I have enquirer via AD and combined price of around £420 blew my mind to be frank. Just thinking about "reasonable" alternatives.