And when you build an ERP in house, you are obviously stuck maintaining a team for that, for forever. But generally the same if you put in SAP. A good friend of mine does SAP integration for a smaller manufacturer in New York. Their full time, dedicated SAP support team is larger than the in house development team for the bespoke ERP for a larger company.
They are similar manufacturers in that they are both multi-nationals, use similar supply chains, etc. And the SAP implementation is more costly up front, took longer to implement, carries more ongoing risk, requires more ongoing cost, and does less.