Possible Clues:

• It's not common, ordinary character ditching upturned luge
• Go slow, entering sunbeam -- this doesn't happen often
• I tarry after ordering scarce object
• Fish circling river -- it's not a common thing
• Tub removed from tributary - it's a collector's item
• Once-in-a-blue-moon occurrence
• A slowing down in network is no common occurrence?
• Factor in a trading card's price
• Scarce item
• Track going round a river -- it's something unusual