13Deals offers the Doctor Who Tardis Large Gelatin / Cake Mold (pictured) for $6.99. Better yet add two to your cart and apply coupon code "DOCTORWHO29" to cut them to $8.51. With free shipping, that's the lowest total price we could find for a 2-pack by $9. This silicone mold measures approximately 6" x 3" x 2".
Only want one? Add one to your cart for $4.96 with free shipping via the above coupon.
Also available is the Doctor Who Tardis/Dalek Gelatin / Cake Mold for $6.02 with free shipping after the above coupon, or get two for $10.62. That's a price low by $9 for one or $19 for two molds.