Ironically, in large scale (SAP-class) enterprises today, the integration problems are often relate to the fact that they are running multiple ERPs they picked up through acquisition and run customized business rules that cannot be cost effectively moved. Look at large scale master data management tools to get a sense of this type of problem.
Much of my work involves mid-market ERP from Microsoft, Sage, Infor, etc. These vendors can give a smaller company an entire integrated suite of tools, with great support, an ecosystem of ISVs fully implemented for $200-300k, including consulting. That remains a compelling value proposition and less risky than hiring programmers, who these companies have no idea how to manage.
One company to watch is Infor. Their strategy involves traditional ERP (usually products tailored for a vertical) at the core, with ancillary products integrated through standard middleware or APIs and delivered through Amazon cloud services.