Amazon offers Prime members The Land Before Time: The Original Movie on Blu-ray Disc / Digital HD for $7.99 with free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, shipping costs $4.98.) That's $5 under our October mention and the lowest total price we could find, outside of the mention below. (It's also about a buck under what you'd pay in-store locally.)
Don't mind picking it up? Fry's offers it for $4.99 via in-store pickup.