Try PartMash
Look around a working PartMash account: a Shopify store with 48 real parts from Holley, MSD, FAST, Aeromotive, Edelbrock, Haltech and FuelTech, three vendor price sheets, and a MAP report waiting to be run. Every price in the demo is made up.
Run the report, raise prices to MAP, undo it, set your retail %, sync stock. Uploading files, connecting accounts and sending email are switched off. Anyone with this link uses the same account, and it is put back every night.
By opening the demo you agree to the Terms of Service, including no automated access, scraping or copying.