for him to be transferred to a Regiment atached to the Court. Such is David Shapard's theory in the annotated P&P and IMO he may well be right. There were such Regiments, for example the Life Guards, who acted as the monarch's bodyguard. They were better paid than officers of other Regiments, which is a bit unfair as generally they would not be in personal danger except in the event of revolution, civil war or invasion. I assume it was because they had more wear and tear on their dress uniforms. It would in theory be possible for Darcy to buy Wickham a transfer to such a Regiment, but I don't think he would do it.