Black-Box SaaS Pen Test

I need an experienced security professional to run a true black-box penetration test against my cloud-based B2B SaaS platform. You will be working strictly from the outside, over the public Internet, with no pre-supplied credentials or whitelisting... (Budget: $250 - $750 USD, Jobs: API Testing, Cloud Security, Compliance, Data Protection, Incident Response, Network Security, Penetration Testing, Risk Assessment, Security Auditing, Web Security)