An unpublished copy of the OSHA COVID-19 Vaccination and Testing; Emergency Temporary Standard is available on the Federal Register website.
https://www.federalregister.gov/public-inspection/2021-23643/covid-19-vaccination-and-testing-emergency-temporary-standard
Importantly, the employers who are "covered contractors" subject to the Safer Federal Workforce Task Force Guidance are exempt from OSHA standard.
From perspective of cost impact: OSHA provides a lengthy cost analysis (section IV. Cost Analysis for COVID-19 Vaccination and Testing ETS, § 1910.501, pdf-page 239). On the first glance, some assumptions look unreasonable. For example: "to establish a written policy in accordance with paragraph (d) of the ETS, OSHA assumes a one-time average labor burden of 5 hours of manager time per firm." This does not seem to account for the time one may need to read and comprehend the 490 pages of ETS. This probably wouldn't be just a single person at larger companies, because non-compliance may carry hefty penalties.