Thanks, All.
@kaiser: Most of the stuff you see is official LEGO. The humans are from their Ninjago range, IIRC. The dwarves are from a collectible minifig series. Gobbos I put together from bits of their Castle series trolls. The cave troll is straight from their licensed LOTR line. Most of the weapons are from third-party manufacturers (you certainly won't see any blood-splattered spears come out of official LEGO ranges); there are lots around these days, and some of the stuff they put out is great quality and detail (c.f., the axes and war hammers on the dorfs). Having said that, as you mentioned yourself, the detail on official LEGO parts has come a long way since their earlier days.
@Cherno: They're not too expensive. An average minifig will cost somewhere around $2 to $3. Equipment's probably an extra buck or so. The scale's probably more of a problem. I usually play with 28-32mm minis. LEGO minifigs are a fair bit bulkier (if not necessarily taller—they just take up more space in general).
—Michael