I hate to tell you this but what you are requesting is absolutely absurd in prices. Mega stones here can be bought for 20pc, which = 20cents. Also in regards to your event thread, events can normally be bought for around 100-300pc, which = $1-3
I can't imagine anyone will want to trade a $25 xbox gift card PER item/pokemon. Just a heads up
Maybe check out other peoples prices and try to match them.