Can I Price-Match a "Percentage Off" Sale?
No.
In the event that a flyer advertises a price which is a percentage off for a sale, the item is not able to be price matched at the store you are price matching too (in this case Walmart). This is for the most part, because the cost may differ from store to store.
Example, Walmart could retail the item for $9.95 and Zellers could retail it for $14.99, with the 50% off, it would be $7.50, Walmart would have to give you a greater than 50% discount for the product, because it would not be a match to the original price, it would make them sell their product for $4.98, no where near the sale price that Zellers has. This basically makes the store with the sale price, the store you "have to" shop at if you want that discount because they know, you can't price match anywhere.
Another example of this type of "sale with no price match possible" would be: Sobey's recent multi- week "sale" which was a membership drive for their Club Sobey's. I don't know if you noticed their flyer (not this week, but in the weeks previous), they were advertising $1.00 members save... in tiny print... it looked like the cost of the item was (example) $1.00... in fact, ONLY if you were a member would you save the $1.00 and thus, you could not price match with their flyer. I called the corporate office about it and said I didn't like their flyer. LOL... it's true, I didn't!
This also applies to the "buy 2 for $3.00" (example) at No Frills. No Frills will price match, but will not price match a multiple item. (I have had no problem at Walmart when purchasing a multiple as a price match, as in the example).