SSO isn't a tax. You either need a single method to disable an account across all providers instantly and enforce password policies globally, or you don't. Do the risk vs reward math and then put the line item in your budget. Get a discount or use a reseller to avoid retail.
Back in the day SAML was the only game in town, SSO was an enterprise feature. Nowadays with oAuth/OIDC, this is a no brainer and you can get a basic setup going with plain Google Workplace (Gsuite/Gapps/...) without the need for anything else.
Yet SSO keeps being bundled in the premium feature list of most of the SaaS products out there, costing 10x to 100x more per user.
14$ sounds pity, but when you take it in the equation of "price per slot * total slots * products * 12 months", you can get to some serious numbers even for a small 10 people company.
Notice I said "slots". That's because the nasty trick lots of SaaS do nowadays to boost their profits. They will auto provision a slot when a new user onboards, but when that user account gets removed (with or without SSO), they will keep charging you for the slot until an admin goes and reduces the slot amount by 1. This is something that AccessOWL can help with, I suppose.