Availability and ease of synthesises are crucial properties that all drug-like compounds should exhibit to be progressed in the drug discovery pipeline. Due to its importance, several approximations for these properties have been developed. In this manuscript we have illustrated some of the limitations of current synthetic accessibility (SA) estimations for use in estimating availability, including the poor correlation between SA estimations and compound price. The practical implications of this lack of correlation are far ranging, since SA estimations are commonly employed for compound prioritization and price is an important variable when deciding which compounds should be assayed. More importantly, most de novo methods for molecule generation are biased to or optimized against simple SA measurements such as SAscore, which significantly undermines their usefulness, as they will consistently suggest prohibitively expensive designs that will hardly ever be selected for progression.