Turbosquid’s current royalty rate is 40% for all artists who haven’t agreed to their exclusivity contract. For those who do accept they will increase royalty payments based on gross sales. The highest royalty rate they offer is 60% but you will need to sign the agreement and have gross lifetime sales in excess of $10,000.
Once you agree to the contract you will not be allowed to post your models for sale anywhere other than Turbosquid. You can opt out of this exclusivity contract but there’s a process that includes approval and a 30 day waiting period. Once you exit the contract your royalty rate goes back to 40%.
Turbosuid is a good place to sell. They’ve been around for a long time and they have a very large marketplace for stock 3D products. The royalty rates are kind of low but they have a full 24/hr support staff that handles a lot of customer complaints and they do file conversions for your customers, etc. So you are getting something out of it.
Just search “squid guild levels” in their support system and it should take you to a table showing the requirements and benefits of their exclusivity contract.
Publishing on more than a couple market places can be a pain so if you’re not up for managing more than one publishing system it might make sense to go exclusive with them.
On the other hand it might be worth seeing what other 3D market places offer and what kind of sales you can get there before you sign anything with them. There is a site called blender market but I believe you have to go through an approval process before you can sell there.