[130] Addressing the issue raised by the appellant that the respondent gains a double deduction for his plea of impecuniosity if the court takes impecuniosity into account in the setting of costs as well as a penalty for a criminal conviction in the form of a fine, Lord Bingham CJ in R v Northallerton Magistrates' Court; Ex Parte Christopher John Dove [2000] 1 CR App R (S) 136 at [4] held:
While there is no requirement that any sum ordered by justices to be paid to a prosecutor by way of costs should stand in any arithmetical relationship to any fine imposed, the costs ordered to be paid should not in the ordinary way be grossly disproportionate to the fine. Justices should ordinarily begin by deciding on the appropriate fine to reflect the criminality of the defendant's offence, always bearing in mind his means and his ability to pay, and then consider what, if any, costs he should be ordered to pay to the prosecutor. If, when the costs sought by the prosecutor are added to the proposed fine, the total exceeds the sum which in the light of the defendant's means and all other relevant circumstances the defendant can reasonably be ordered to pay, it is preferable to achieve an acceptable total by reducing the sum of costs which the defendant is ordered to pay rather than by reducing the fine.
A number of Supreme Court authorities have followed this reasoning (see Morgan v Biddle [unreported, Supreme Court of Western Australia, Wallace J, Supreme Court Library No 2845]; Thomas v Schwager [unreported, Supreme Court of Western Australia, Parker J, Supreme Court Library No 970719] and Koenig v Fraser [[2000] WASCA 262]).