Well I see both points.

Skaar is making the point that inflation of the hobby in general, not just sealed sales, hurts the collector / gamer. That's true to an extent, when a Little Samson cart goes from $100 to $300, someone who wants to play it is genuinely "hurt". Of course there's still emulation, but most gamers prefer original hardware, especially on platformers which require good timing / coordination.

However, the collector also benefits from the value spikes, as their collection is now worth more. The argument then becomes "But if the person is truly a collector, they aren't selling so they never see a penny of the increase". That's also true, but how many times have we seen a collector sell out for a true need? Loss of a job / loss of housing / death of a family member / etc. Collectors don't always plan to sell out, but when they have to, valuation does matter. So the inflation helps them.

And Beagle's point is that high end sealed sales does not affect loose cartridges, which I completely agree with. You might get a bonehead trying to sell used stuff at new prices, but it's not like you have to search for an eternity to find a $2 NES Tennis cartridge. You are merely inconvenienced by having to sift through a couple more bogus listings to find something at the price you want to pay.

Just my .02. The only one truly hurt by inflated prices are the brand new collectors who have nothing. But normal gamers / collectors also benefit by having their games increase in value.