> Each of the old IT staff in the old system you can replace with 3-5 SAP consultants.

Is this facetious, or unintentionally so? Do you mean you need to replace one in-house staff with between 3 and 5 and presumably very expensive consultants?

One of my first recruiting jobs was hiring ERP consultants (SAP, Siebel, PeopleSoft, Oracle) and even 15 years ago, these people were easily making $100/hr, and if you were specialized (esp. with the supply chain modules), you could get up to $200/hr. They rarely had programming skills outside of SQL and Linux understanding.

Ah yes, in typical "enterprise software" fashion, blame and gaslight the victim

From experience, the factor is more like 5-10. Depending on the complexity of the existing solution, and depending on the wealth of custom implementations, of course.

SAP is better though as a set of libraries than a solution, and it's worth a lot precisely because it will fit whatever whacky process an organization has so that the org doesn't need to change itself while adopting the software.

The most obvious failure modes are going for the lowest bidders incentivizing them to deliver with a skeleton crew, trying to nickel and dime the budget cutting features or their scope or straight up coming at the table with no documentation of how orgs own internal processes actually work.

I know of no project failing because of sap or their consultant on its own without any of the above comorbidities.