[Jiro]

Prices on Steam are set arbitrarily. Getting things at "50-90% off" could just as well be described as sometimes getting them at normal price and otherwise getting them at 2-10 times normal price.

It's not a used game market unless you can transfer it to other people an unlimited number of times without the original company getting a say.

[somenameforme]

I have no idea what world you're living in. No prices on Steam are anywhere near 2x the "normal" price, let alone 10x. Companies that set their prices to the typical MSRP are generally seen as largely out of touch (with Japanese companies being particularly renowned for this), let alone above MSRP.

[Jiro]

50% off is equivalent to sometimes being normal and sometimes being 2x normal. Likewise, 90% off is equivalent to sometimes being normal and sometimes being 10 times normal.

If something costs $10 "normally" and is $1 with a "discount of 90%" you can just as easily say it costs $1 "normally" with the $10 being 10 times "normal". It's purely arbitrary which one you label as the normal price.

[somenameforme]

I have no idea what argument you're trying to make, or if this is just some bizarre semantic thing. The normal price is the non-discounted price. In some domains like clothing where there is a perpetual 50% off a price that never is set that high, that's an exception - but one that has nothing to do with Steam.