The price is down to less than $2 for an average quality disk. They are much more flaky than single layer so expect a few coasters and maybe an average cost of $3 including wastage. May be a good idea to buy packs of 3 until you find a brand that works well with your burner. The max write speed will probably be 2.4x so it's a long slow burn.
At this stage in their development, I would not use them for vital information storage.
Starman*