I was having a look through some different ranges of figures earlier (because, obviously, I just don't have enough unpainted minis lying around!)
I noticed that Museum Miniatures are having a pretty impressive sale, at 25%, on their entire range. MM cover biblical through to WWII in 15mm with an comprehensive choice of figures. Packs are either 8 infantry (usually single pose, with at least two poses available) or 4 cavalry, with artillery and accessories also available. At the reduced price of £1.88 per pack, that represents a fair bargain.
Quality wise, I'd put the MM as between Essex/Minifigs and Xyston in quality i.e. right in the middle of the range, good quality, but not the best. Delivery in the UK is pretty reasonable, but have no idea about their international charges.
So if you're an after some 15mm historicals, you could do a lot worse than have a look at Museum Miniatures.