Is there a way to get the following kind of pricing tiers (as found in Sales/Pricing) for an Item record, but on the Purchasing/Inventory? We are considering using a custom Record Type to do this, but if there's a better way... please let me know!

If you have advanced procurement you can use purchase contracts with tiered pricing

Have you checked the Quantity Pricing Schedule? They’re available as standard, without the need of custom or Advanced Procurement, even though they have to be defined at vendor level and then associated to items. https://docs.oracle.com/en/cloud/saas/netsuite/ns-online-help/section_N2183677.html#To-associate-a-pricing-schedule-with-a-vendor%3A Have a look, consider the bottom part of this page 🙂

Thank you, @michoel and @Tommaso Pasetti , I will check those out!