Recently the Cartel led by Shell was exposed by the European regulators and the was fined to the tune of price fixing on various petroleum products.
For Bitumen, there are no posted prices except for some compiled prices from some paid subscription services ; marketers rely on a number of pricing formulas that reference various posted crude qualities.
Market pricing is seasonal with higher prices during peak season like summer being the norm due to higher demand for bitumen and other bitumen derived products.
On the Other hand,
Singapore, Malaysia, Thailand, although except for Singapore, the rest of the regional economies , being net importer, the pricing is closely followed with each other, and which is not affordable for re-export for the developing nations.