I assume this is equivalent to Black Friday but in Canada. Yeah, I worked in retail during Black Friday. Not really sure if it's a fair comparison though because:
1. the day is known and mentioned before hand so of course a lot of people will be sniping. In PokeMMO people are literally sniping like it's boxing day 24/7.
2. It'd be the equivalent of a customer teleporting to the item as soon as the stores are open, and then teleporting to the front counter. They still have to walk to get the item which still makes the .2 seconds that this happens in unreasonable.
Reaction time is on average .25 seconds, but you also have to account for the time it takes to process this information, and the time time it takes to press the buttons to buy the item. I'm not saying .5 seconds is completely unreasonable for the item to be gone. I'm saying .2 seconds is quite literally impossible without some form of macro/script filtering what is and is not good. I don't mind being disproven on this and I'd love to meet the human being who was able to snipe my 99 Leppa berries literally immediately as I put it up and ask them how they did it. It'd be nice if they showed the person who purchased your items on the GTL.
To be honest, this shouldn't even be a problem because it's so easily prevented by putting a 2 minute wait for new items placed on the GTL. Not saying that stuff wouldn't be getting immediately sniped still, but it at least prevents the user from being screwed over from such a rookie mistake (yes, I am stupid and did not look closely.)