This set, which comes with two copes of three designs, currently retails for £5.77. All three designs share a common Egyptian theme, with plenty of scarabs, Ankh, robes and details which scream Egypt (and are perfect components for Thousand Sons).
These legs have a distinct Mark II/III Power Armour look to the, with segmented and riveted shin and thigh plates, and reinforced front armour. These would make fantastic Horus-Heresy (or post-Heresy) parts for a Thousand Sons force, as they are not overtly chaotic, and fit that particular legion's themes and design.
In terms of pose they are much straighter than, say, GW legs, giving the models you make a noticeably taller-standing pose. As seen here, the model on the right's (Kromlech legs, head plus a few other bits) eye-level is a good 0.5cm /1cm higher up, which makes for a much more imposing model.
For any Thousand Sons player, this is another must-buy for a great looking and unique force. For best value-for money, mix these in with other parts. Whilst less than a pound a pair is OK value, if you use a lot of these, the costs will add up. This can be said for any set of bits from any company though.
In short, this product gets two thumbs up, and I would highly recommend it, even just one set; they would be perfect for veterans or characters if you do not want to commit a whole army to them.