I haven’t noticed a difference in most things. Some things are cheaper at Walmart, but they also often have companies make worse versions of products for them just so they can sell them cheaper.

Clothes are notorious for this.

"Wow, [mid-tier jeans brand] is only $16/pair at Wal-Mart, and they're $40 when you find them on sale on [jeans brand]'s web site. What a bargain!"

... but then it turns out they're not the same thing, even if they're made to look very much like they are even down to the labelling, and in fact the manufacturer produces a separate low-end- and outlet-stores version that's much worse than their standard product.

A different phenomenon but somewhat related is when good brands have an unusual sale item (not a close out). It seems to be where the MFG had a bad run and they’re noticing a higher rate of returns so they put them on sale. It’s not worth it, get the full price version and avoid the defects (like seal quality, adhesive quality, material quality, etc.)

For an equivalent item, Target is usually not much more expensive, if any. But, Walmart carries cheaper alternatives and a wider selection than Target.