My apologies for my late response.
For the most part, recipes are a matter of personal and customer preference, and what is available in your area and are affordable. I find Coconut Oil to be a bit drying in soap so I use it at 20%, but I have a customer who is allergic to Cocoa and Shea Butters and so I use CO at 27% for her and she loves it.
I am including my recipe down below, even though I saw what you wrote about Palm Oil and Cocoa Butter. The PO I purchase is responsibly and sustainably produced; I pay a little more for it, but it's something that I support. Cocoa Butter isn't cheap here in the States either, but I get a good deal on Shea Butter and so it works out in the wash. And honestly it wouldn't matter if it didn't because I like what CB brings to the table and I'm about producing a quality bar of soap, and quality is not cheap.
I have been a 'maker' of things my entire life and yes, it's not cheap. Cooking, baking, sewing, embroidery and cross-stich, quilting, crocheting and knitting and now soap making. Part of it is the labor which has been reduced through industrialization and mechanization, part of it is the stuff it takes to make these things. When I first started making soap, I was buy in small quantities. A pound of Cocoa Butter Wafers is $12.00...if I buy 5lbs it's $9.60 lb, if I buy 26.5lbs it's $7.41lb. I've gone from paying $2.87oz for 2oz bottles for my FOs to $1.71oz for 16oz bottles. My next step is 5lb jugs which will bring my cost down to $1.56oz.
35% Olive Oil
20% Coconut Oil
20% Palm Oil
10% Cocoa Butter
10% Shea Butter
5% Castor Oil
33% Lye Concentration
5% Super Fat
1 tea Sodium Lactate PPO
1 tea Kaolin Clay PPO