Not so rare, back in the day, as I recall. They just didn't sell well, the RoR sets that sold well (of the original, 1st Ed. sets) were: Bugman's, Grom's and Golgfang's, to a lesser extent: Mengil's, Harboth's, Oreon's, Knights of Origo and Disciples of RR (when they were released). I picked up an entire regiment of MMA's Death Commandos including the three original command in a sale at my local model shop in around 1985/6, sadly I sold most of them sometime in the late 90s on Ebay, although I still have a small unit in need of painting. Lovely figures.
I recall two stories about them, that may, or may not, be true!
1. They were based on an early campaign between Tony Ackland's Men of the East (presumably mostly the very early Citadel Dark Age Arabs) and some other Citadel stalwart's High Elves. All the early RORs grew organically out of campaigns amongst Citadel staff apparently, the Grom-Bugman-Golgfang RORs were all part of the same 'storyline'. Interestingly, if you look at the early C range of 'High Elves' you'll see many Middle Eastern and Oriental influences - in fact some make perfectly good Arabs or Samurai with minimal/no modelling work.
2. All the RORs were released with four 'command figures': Hero, Standard Bearer, Musician and Champion. The original Eunuch Champion was a failure(?) because it didn't cast well, perhaps(?) and due to that specific ROR not being the most popular it was sometime before they brought out a replacement. My feeling is that they only ever brought out a replacement for him because rules for him had already been published. As he was released after the big slotta change over, he was released on a slotta base, the only MMADC to ever be a slotta figure, as the rest of the ROR weren't re-released, unlike, for example: Grom's, or Bugman's. That is why he is so rare, but the rest of the unit aren't particularly.
'Men of the East' were never the best selling releases of Citadel, although over the years they (mostly the Perry 'twins' who have a thing about the Middle East) produced quite a few odd 'Arab' type fighters - enough that I have managed to build a small Arabian army mostly made up of later Citadel releases with some Harlequin/Black Tree.
All that aside if anyone does have Hasim the Eunuch at a reasonable price I'd be very interested (as I'm sure a few others would), a couple of years ago I narrowly missed buying him mis IDed on Ebay, I forgot to bid due to family distractions... and he went for about £2(!)
The figures look like 15th/16th Century Mamluks and the command resembles Ottomans, so wouldn't be hard to proxy.
