1. If what you ask for was completely out of budget, they would not have spent time interviewing you.
2. If you are happy with $30 but still quoted $40, and now you accept $30, you are opening a can of worms. It means, you CAN and WILL be pushed around financially as long as you are in the company.
3. If you have faith in your skills, walk away. You will always find another company willing to pay you the money you ask for, as long as it is realistic.
If I was in your place, I would have walked away if it was a penny under $40.
There are quite a few things I disagree with in the post.
> Every developer has a Github profile. If their profile is new, yet they say they’ve been coding for 10 years — you may want to gut check.
There might be developers that just does not want to commit to public projects. It is possible that the developer is bound by NDAs that they can't share customer work. I know I fall in this category.
> It’s 2019. If you’re hiring someone who works on the internet, you will be able to find them on the internet.
Again, incorrect. I intentionally make effort to remain as much of an online ghost as I can. If you search for me on Google then you WILL find a profile, but that is a profile I am forced to maintain and may or may not be the person that the profile describes.
> Often it means they didn’t do the work, and will disappear once the money is sent.
Possible, but it might also be that the people are running on razor thin margins and have bills to pay. The whole idea of selection of contractors on Upwork and similar websites is mainly finding the cheapest guy. If someone in India is beating others in price, it means that there is really not a lot of runway to let an invoice sit for weeks. The guy has to buy bread you see....