I run a blockchain development company and I've worked on all levels in the past. So I'll give you my perspective on this.
Fiverr is only for the absolute most basic of tasks. Don't hire anyone there for anything more than design work. You can get a cheap ERC20 there too if you want one for testing. The ERC20 tokens you get there though usually won't have a lot of customization to them. It'll just be a clone of an existing token.
Upwork and Freelancer are great resources for individual developers. If you have a small project, maybe just a proof of concept, then this is the way to go. You can hire a person there to accomplish a lot for less. There are a few hangups though. If you aren't technical yourself then you can easily hire a poor developer. The better the developer the busier they likely are. It's a give and take in order to save money with a freelancer. They may disappear midway through the project. You have to develop a lot more trust when they are handling your private keys and other sensitive information. The less you know the worse you will be using this option. However, if you are very technical and good at project management then the better off you'll be.
With blockchain development companies. The ups and downs here are obvious. You have a collection of experienced blockchain developers working strictly on this one type of software. It makes it an expensive option. These are professionals who want to get paid for their skills. However, there are many advantages. They can likely accomplish everything you want correctly the first time. This may save you money in the aggregate as you won't have to pay for so many revisions. It may also save you a lot of time. Blockchain companies can also use their experience for consultation. They can contribute to the vision of your project - whereas a freelancer will likely just do as you say whether that helps or hurts your project. They've also been around long enough to know they aren't going to run off with your data.
If you need any help I can answer any question at email:
eric@infraexdev.com