Well, since your drink cost 2 splinter (or 2 copper), you don't imagine that a decent bribe would be a shard or two (a silver or two).
Also... for everyone's benefit, I'm going to lay out the monetary system again, I think I had it in the old thread but lost it.
Traditional Coin: These are your standard copper, silver, gold and platinum affair, although the stamping is sometimes different depending upon region, generally based off of weight more than anything else. Official businesses under the eye of the Mythar refuse such coin, more out of fear than for want of the precious metals. People dealing in traditional coin are often looked upon with suspect by any who are Mythar sympathizers.
Mythar Coin: These are quite different from standard coin, splinters, shards, crystals and veins are the names of the equivalent pieces. Physically they all vary slightly, but they possess an odd property in that they can be joined or broken up into lower or higher forms. Literally speaking, 10 splinters make a shard, 10 shards make a crystal and 10 crystals make a vein. They are incredibly hard to forge as they possess some measure of power which allows them to meld or break apart. Additionally, when held to a light source the dark purple crystals have different color sheens. Splinters give off a dull gray sheen, shards a dusty blue, crystals a bright red and veins a vibrant purple.