If you want to use themes/plugins on your business site and if you have enough money to afford the price then please purchase from the developer to support him/her. But if you can’t afford/you want to test before purchase then you can go for cheaper/free.
But unfortunately 99% free sites are fake. Malicious codes found on those free sites. As per my personal experience i found those sites are safe which are sell in cheap price.
In most case i can’t afford themes/plugins to purchase, so i look for free. Test them with VirusTotal if the files are clean then i use them. If i unable to manage them free then i look for cheap websites.
From 2017 i developed few sites to provide cheap WordPress themes and Plugins. You can visit my sites.
After serving a lot of customers, i finally get Adsense approval on 2021 for both of sites and decided to make those themes and plugins for free.
So now you can download cheap WordPress Plugins and themes for free 🙂
But if you can afford please support the original developer by purchase from the original source.