NameCheap provides auction services through third parties for certain domains. You're confusing a poor experience caused by a bad response from one of these third party services with them doing something malicious. GoDaddy actively sells lists to "Executive Domain" accounts specifically so they can make money off the resale of these domains. NameCheap is just listing domains from third parties that provide auction services and sometimes they either don't get a response (so they show the general "buy" option) or they get an incorrect response (so you get an error). You're suggesting malicious intent on the part of NameCheap without any evidence that it exists.
Also, how is what you described scammy in any way? There's a difference between an error showing up for a domain name vs. a domain name showing as available and then later in the day showing up for an exorbitant price on the same site. NameCheap even labelled that domain for you as coming from a third-party but you're choosing to ignore that to sell the narrative that they're scammy.