I'm interested in 100GB MDISC optical media for long term backups, i even bought an external BD writer, however their astronomical price (14€ per disc) makes th

I'm interested in 100GB MDISC optical media for long term backups, i even bought an external BD writer, however their astronomical price (14€ per disc) makes them a lot less attractive. Whereas 25GB BD-R are 0.26€ per disc, the 100GB BD-R (non MDISC) are 8.21€ per disc (also obviously overpriced). PS: 25GB MDISC are 3.25€ per disc