What is the open source equivalent to FIPS 140-2?. There are businesses that use it when doing business with government. Since a lot of us wont be doing business with the government, is there a similar standard open to the rest of us that can give corporate customers the peace of mind that their data is safe?.
There is no open source equivalent and there doesn't need to be one since FIPS 140-2 is not restricted to closed source software. For example there is a FIPS 140-2 certification for selected versions and configurations of OpenSSL - see https://www.openssl.org/docs/fips.html.
The certification i imagine costs a fortune that's why i am asking if there is one that wouldn't cost too much.
A certificate costs something since there is actual work involved in certification - both from the one applying for the certificate and from the agency which does the certification. Such a certificate stands for some level of (kind of) verified security and such security and verification does not come magically from just handing over some money.