Where the cost sits
Non-licence costs often represent a large share of total cost of ownership: implementation, professional services, integrations, API usage, storage, support tiers, training, change requests, and client-side effort.
Why pricing models differ
A supplier with lower seat pricing may recover margin through professional services, usage charges, integration work, or support tiers. Another supplier may look more expensive upfront but reduce delivery and integration effort.
A useful TCO model
A credible comparison needs a detailed scope, realistic usage profile, implementation assumptions, support model, contract term, exit terms, and sensitivity testing. That is what turns price comparison into commercial analysis.