Watch out!!!  Currently, eBay is flooded with very low quality bootleg copies of BBC's "Planet Earth" and "The Blue Planet" DVDs.  Note:  I've already struck a nerve with bootleg sellers with this guide, confirming that it's preety darn accurate ;)

Bootleg DVDs have a MUCH lower resolution picture that standard DVDs.  DVDs are dual-layer, meaning that they hold twice the info that the bootleg's single-layer DVD-R, DVD9, Baby DVD, VCD, etc, holds.  A visually stunning program like these deserve more than what third-rate Asian cartoons receive.

Before purchase, view the seller's / PowerSeller's other items.  Mostly or only the same title?  Be suspicious. 

Review their feedback:  Look for the negs. Why? Some people don't know that they received a bootleg, or don't care.  You could see a lot of "happy customers", possibly due to a "Leave me positive FB or I won't refund your money" situation...  Why send your good money, just to receive a bootleg from China that the seller bought for $3?

Excessive shipping charges (i.e. 12.95 Priority shipping):  hey, if the seller is dishonest in one dept, why not another?

Not sure if you received the bootleg version?  How to tell without opening the plastic:

The current bootleg version being sold:  In the description on the back, look for the ITALICIZED PRINT:  In one section where only the name of the program is to be italicized, the scammer who retyped the smaller print italicized to the end of the line (among other punctuation errors).  BBC spent a lot of money on this project;  they wouldn't have forgotten to have it proofread.

If it says "DVD9" on the bottom of the package or on the discs... IT'S A BOOTLEG (Most bootleg DVDs from China say "DVD9" on them)

If the PRINT on the BOX is a little BLURRY... IT'S A BOOTLEG (Scammer scans the real packaging, making it blurry when it's "reprinted")

If  "PROOF OF PURCHASE" is printed directly on the box (would have to cut through the heavy cardboard to remove)... IT'S A BOOTLEG ("Proof of Purchase" labels are meant to be removeable for mail-in offers, etc)

Bootleg DVD sellers & PowerSellers can be reported to eBay.  You can have your money refunded through PayPal by using "Significantly Not As Described".