In industrial pump quotations, which cost items are often hidden or added later?

• Conclusion: common hidden items include mechanical seal, coupling, baseplate, motor and spare parts.
• Confirm whether the quote covers motor, baseplate and coupling or only the pump head.
• If seal brand and flush plan are unspecified, upgrades will incur extra charges later.
• Different flange standards such as ANSI or DIN may add machining costs.
• Require the quotation to list wear parts, unit prices and warranty period to avoid later disputes.