One dressmaker here offered to make clothes for our dogs. My wife immediately acceded because the cost is less than 50% of dog clothes in the store. Of course, it would be cheaper to have the dog clothes made because those in the store are mostly imported hence the higher cost. But even the local ones are more expensive. What’s best in having the dog clothes tailor-made is the size that would exactly fit the dog.
Having a large dog meant that I really had to search for outdoor coats for the winter. I wanted to get them jumpers as well for when I was out and they were home alone with the heating off. It was a challenge finding anything the correct size. In the end, I found a little market stall in a town ten miles away that was able to order me what I wanted.
I'm not much of a dog-lover or a fashion-lover, so it really has not entered my mind to buy clothes for my pets, especially that we live in a tropical country too. But I think that if you could save money and the quality of work of the tailor or seamstress is good, then you should definitely just use their services instead of buying pet clothes in stores.
I don't see how dog clothing would be much a bargain anywhere. Note, I say this because dogs are already protected against the cold and the clothes won't help them against the heat. Anyway, one exception might be a really cold place like Alaska - assuming, though, you're not keeping the dog inside.
I think it's ok for animals to wear coats in the cold weather but I really don't like any other kind of clothes for dogs. I remember my nephew buying a christmas jumper for my Jack Russell and she hated it. She managed to wriggle out of it and then bite holes in it within minutes of having it put on! Most dogs do not like the feeling of wearing clothes and even in the winter months their natural coat becomes thicker to protect them against the elements.
I am not sure I would want to be spending money of anything related to dog clothes, so I suppose if custom means scrapped together for free than I could be interested, but other than that probably not.