L. Adleman, "Molecular Computation of Solutions to Combinatorial Problems", Science 266, 1022 (1994)
Nucleic acid computation vs electronic computation is rather like SpaceX vs traditional rocketry, in that in traditional rocketry you have to build your entire infrastructure and medium from raw materials each time you want to do a new launch.
Adelman is right that process of oligo synthesis is energy cheap and amortizable, but he's not a chemist: the dNTPs themselves are not. A nucleotide triphosphate is not an easy molecule to make by virtue if their instability, and their usefulness derives from their instability.
Also really fun would be writing your unit tests to make sure the DNA algorithm you've programmed was acutally correct.