Can an employer legitimately reject a disabled job applicant on the grounds of the costs/disruption to its organisation?

Under s.20 of the Equality Act 2010, employers have a duty to consider if there are any reasonable adjustments to working practices and premises that they could make to remove or reduce any substantial disadvantage that a disabled person would otherwise face if he or she were employed. However, if an adjustment would cost a high sum in relation to the employer's resources, or if making the adjustment would cause considerable disruption to the employer's business, it will, arguably, be reasonable for the employer to decide not to make the adjustment.