In a nutshell, if you have a choice and don't know what would be better for you - a freelance translator or agency, always choose agency. Based on my personal experience, agency provides more accurate and professional translation. By the way, Ad Gloriam is a good option https://adgloriam-translations.com/
What do you want to translate and what languages are you interested in? I know that sometimes you can save money and get good enough machine translation, but if you want to translate documents, manuals, instructions, adapt your game or website for native speakers, then you need to find high-quality human translation. I know that you can find both services on this site translate.com/ , because I use it often, as it has the largest selection of languages and even machine translation is better than many of those that I have used before. I compared the cost of translation services in different companies, but finding the local, who sometimes can make translation better than specialists in such companies, turned out to be much cheaper. If you want to pay an honest price for this service and get well done work, then I think you should visit this site and look for the contractor for your order.