Every ERP will be "customized". It has to be - provide your own chartfields, business units, workflows, decision points, etc.
It's the amount of the customization that makes the difference. I've been on ERP implementation projects that were 28 days long, and 5 years long.
I am the "expensive contractor", and I have never ever in 20 years met another expensive contractor who did not fight, tooth and nail, to minimize customization. From the initial business requirements and scoping, to the constant CRs likely to be encountered during implementation.
On average/as a generalization, contractors/consultants have seen many businesses and see the commonalities, seen dangers of customizations, and fight them; clients know only themselves, believe in their uniqueness, and don't have a good vision or image of themselves post-transformation - how they could possibly do things differently. Consultants want their Time & Material bills, sure; but even more want successful project and references - not to mention sanity, semblance of life, and feeling like they did good work and helped the client.