How many public methods do you have to test? Do you have any static analysis that lets you know estimated path numbers through the methods?
I work full-time for a Fortune 500 company in Arkansas, U.S. The application I work on is Java utilizing Spring Boot with an Angular front end. I have my degree from San Diego State University, San Diego, California, U.S.
I expect that I can write tests to cover approximately 1000 lines of code with most edge cases and all happy-paths for this price in about 2-3 days. If your project is larger, this is about how much work I would do for the quoted price.