The Octopus Salary sacrifice is not particularly cheap when compared with motability, my company run the scheme. I picked up a Ioniq 5 Ultimate from motability in September the advance payment was £2,000 add in the approximate monthly PIP payment of £300 x 36 = £10,800 so total payment over 3 years is approx £12,800
The Octopus salary sacrifice scheme, no upfront payment, but the last time i checked, the Ioniq 5 ultimate (for my salary) was a net payment out of my wages of approx £550 per month, so over 3 years £19,800 so a good £7k more than motability.
They do however, offer a much wider selection of vehicles and specs.