Filtering Out Users for my Freelance Website

I've created a freelancer/upwork clone website, and what to make sure that I can attract as many users as possible to the website, but I also dont want to jeopardize the quality of the website as I have scene on sites like this many individuals who are not natives come and reduce the quality of work on the website.

I do not want to require that members take tests and what not, and want the website to resemble amazon or ebay in that its quick and effortless to ask for work and hire someone.

Does anyone have any tips?

hard to say...

I'm not even sure where to start.

I guess the first thing you should do is to require people charge a minimum per job. That should keep people from low balling other people. For example, the minimum someone can charge for a 500 word article is $50, or the minimum for a coding project is $4000. (Just as an example.)

Everything else I can think of has a workaround:

Check IP address - Proxies/VPN
Identification - Photoshop
Social Security Number - Can be stolen
Credit Card Verification - VCC
Phone Verification - Can be bought/faked
Address Verification - Can be bought/faked
Tests - Can have someone else pass them for them

Maybe make the site invite only for sellers, but allow buyers to sign up freely.

Idk dude. I got nothing. I do see what you're trying to do, as the quality of Freelancer and Upwork has gone downhill tremendously. But idk of any solid, effective way to keep low quality sellers out of places like that. You'd probably have to rely more on client feedback and monitoring sellers than anything.

Hopefully I gave you a starting point though.

Block all third world countries via htaccess

I've literally seen all of the same topics from OP cross posted on Reddit. Not sure what that's about, considering the person never bothered to return to follow up on their 'pressing' questions. Wouldn't be to get their post count up. No, couldn't be