I dressed as Slash last year for halloween and needed tight leather pants, rather than the most common mens leather pants that are cut like loose jeans.
After a lot of searching online I discovered that while mens' leather/pleather/vinyl pants were expensive and kinda hard to come by, womens' were everywhere and super cheap (esp. on eBay). I got a pair of skintight leather pants (womens) that fit me perfect for about $12 on ebay.