Oh... and I'll stress this again. Monetary value has nothing to do with rarity. Something is not rare simply because it costs more money. Although something deemed as rare can effect value simply because of supply/ demand.
Oh I completely agree. Value of anything is simply what someone is willing to pay. And if enough people are willing to pay a certain price, then it becomes market value. people are paying more for the commercial guns now, so their market value is going up. Heck, that really applies to all sks's, as even regular nothing special models are going for twice as much as they were a few years back.
Rarity is just how uncommon something is. Something can be rare, but it's only valuable if people want to pay good money for it. For example, a misprinted comics book could be rare and super valuable, but a misprinted newspaper is worth zero.
And please don't think knocking the old military guns...I love them! I'm just commenting on the trend that the commercial models are going up in value...and that means people want them.