Guaranteed buybacks... Good or bad?

I think I've mentioned my "competitor" from when I first opened.
If you missed it, they were a place that offered a ... guaranteed buyback... at Grey Sheet bid ...OR... 20% per annum!!! "appreciation" factor.
They bought so many sliders and re-"flipped" them into Ch BU flips... (this was before slabs) that it was impossible to compete with the pricing OR the "guarantee."`
Anyhow, they scammed so hard that they had to FLEE the country. Interpol and everything on the case.
But... I'd like to mention the ...other...guarantee that I've seen too many times to count.
"You worried about the price (let's say $500)....well, if you don't like it I'll buy it back for... $450. Anytime. "
Yippee! A "guaranteed" loss of fifty bucks.
Yes, it worked. Again a hard thing to ...compete ...with as my policy was that I would always buy coins.
For the current market.
Comments
As described, that's really just a return policy with a restocking fee. Perfectly acceptable throughout all of commerce.well, except for eBay who all but forbids it. LOL.