Liz TS,
"...it may sound dreadfully cheesy but that is most often the way it panned out, certainly in the first war and the early years of the second.

Officers commissions were bought rather than earned so only those with money could afford to be officers. After a few years, the middle officers (Lieutenants, Captains, Majors) were lost in action and promotions had to be made up through the ranks. If you had enough money you could buy up a Major's commission without even donning a uniform..."

I think you will find that you are little out of date with this assertion.
The purcase of commissions was banned under the 1881 "Cardwell" reforms, while the ability to obtain rank without attendance tended to have been dropped sometime about the end of the Napoleonic/Regency perriod.
Certainly there was prejudice in the selection of those for commissions, in the Great War, many of the (original) officers for "New Army" Battalions were chosen on the basis of 'background' and the school attended, partly because so much was run on the "Old Boy" network, and partly because it was beleved that those of the 'proper' background developed a natural ability to lead.
Peace time commissions were not bought, after Cardwell, however, there was a degree of "finantial selection" in that an Officer's pay (especially at the lower end) was insufficient to cover his expenses (tailors' bills, Mess Bills, "extra-Regimental" activities etc.) - more so in the cavalry than line infantry.

Regards

Walrus