Here in Canada, depending on the brand, 3-packs of DVD+R DL media range from $19.99 to as much as $39.99(!!!)
Luckily, two weekends ago, FutureShop had the Maxell DL 3-pack discs on sale for $9.99, so I bought one, even though I can't use them until this weekend at the earliest, needless to say since I'm on vacation till then :P
And I like the Mini DVD-R's too. In fact, speaking of Mini DVD's, some anime companies (I think ADV Films in particular) are selling 1-episode Mini DVD discs of titles like "Noir" and "Azumanga Daioh! The Animation", in single volumes, and they're pretty cheap too, so I think that's a clever way of marketing them to the Japanese/anime fan communiuty to build up more interest.
Whether they sell them at HMV or FutureShop here in Canada though is another question to be asked (although I know the movie "Metropolis" (the Osamu Tezuka-based version, not the 1984/early 1900's live action version) also comes with a bonus mini DVD disc, and I believe was the first anime title to ever do so!)
But getting back to the recordables, yes they are a bit expensive, but I think they're reasonable.
It's a shame that they don't have dual-layer mini DVD-R's :(
Hopefully, Blu-Ray will have dual-layer mini BD-R discs (they ARE developing 3" BD/BD-R/BD-RW discs for sure!), or even better, 4- and 8-layered mini BD-R(W) discs as well, since they're currently developing BD discs with those layers, each one consisting of 25GB of recordable data space (for 4-layer 100GB and 8-layer 200GB discs), of which should be out around 2007-2008.