Well...
I learn that lesson still.
Normal Bench rate is between 30-45 per hour and materials.
Some people charge more, some charge less, but that is what I am comfortable with.
I would guess that each custom halter would be between 90-100. Just because they order more at one time does not mean they get a discount, that only means more work, and wear and tear.
I think I am pretty reasonable, and fair on folks. They want custom stuff and I give it to them; at a price I would pay if I where them.
The general rule for carpenters is time and materials +30 percent on top of those numbers combined for oversights.
Being a carpenter I like to take the same approach to leather.
Maybe some other folks will chime in, but I think most people don't like to talk about what they charge, but it is something that should be talked about a lot more.
I see people making custom guitar straps for 75 bucks when they should be charging 150+ so I guess it just boils down to what do you feel is a fair price for what you have done, and don't be afraid to show some pride in your prices!
I give away a lot of small stuff like bracelets and little stuff like that all the time because I make those and wear them until someone says "Hey that is cool I like that"...then I just say oh ya , well here it is yours:) Normally almost every single time they come back for more real stuff.
I call it leather chum...hahahaha LOL.
Anyway, maybe this helped maybe it didn't, but I thought I would just throw down the hammer and try to make a dent for ya:)
I would call them and tell them, hey after configuring out all the costs this is the price...but I am willing to split the difference. So 47 should be a fair enough upgrade for ya and still fair to them...and lesson learned. You used the best of the best materials; so it is what it is...the best! So now it is time for them to pay for the best! Whats a few bucks between friends anyway??? I am sure it won't be a big deal.
Another lesson is not to give a final cost up front only a ball park estimate and tell people it could be more, but you really don't know until it is done and during the time you are working on custom items keep in contact with the client to let them know how it is going and send pictures that way they feel like you are doing everything in your power to stick with the plan, but they are a lot more understanding when and if you have to tell them the price is double what you originally thought. IT DOES HAPPEN!
Anyway, best of luck!...to all of us:)