Amazon UK offers the Jurassic Park Premium Collection on 3D Blu-ray / Blu-ray / Digital HD for $14.69 (£11.99). Add it to your cart and it drops to $12.24 (£9.99) at final checkout. With $3.77 (£3.08) for shipping, that's the lowest total price we could find by $5. It includes Jurassic Park, Jurassic Park 3D, The Lost World, and Jurassic Park III.
Note: Although the movies themselves will play on US Blu-ray players, the extras and special features may not.