I have recently thought about burning some data to Blu-ray and therefore looked for some cheap blank discs. To my surprise, higher density Blu-rays seem to be much more expensive than lower density ones. In my country (Germany) for example, I could buy a 25 GB BD for 0,44€. A 100 GB BD would cost me 8,77€! At that price, it would be more efficient to store 100 GB on four 25 GB discs instead of one 100 GB disc (1,76€ vs. 8,77€). Sure, if it is one file I would have to split it first and combine it again when I want to access the data, but that effort seems to be worth it.
Why are high capacity Blu-rays so much more expensive, especially compared to HDDs or SSDs where the price per GB/TB usually drops with higher capacity?
Have a look on ebay, there are some good deals to be had. You could probably get an LTO-5 for around $150-200, although you’ll need a SAS controller and cabling, which could add an extra $50. So the initial cost is definitely higher, but once you’re past that, it’s much nicer to have large 1.5-2.5TB tapes than lots of discs.