is there any cheapest way to get netsuite sandbox account with sample data

A NetSuite sandbox will give you a single SandBox account which you can copy over data from your production account, plus you will get empty development account into which you can create/import data.

I've always wanted something halfway between Sandbox and Dev. Replicate my Production environment w/ full customizations, but no data.

You could bundle, or use the new “Copy to Account” to move over stuff you need into the Dev account. Or use a Sandbox, and then “Delete all data” 🙂