Nuendo 5.5.6 on OSX 10.9 Mavericks

Geeez, a year later and still struck with paranoia when considering moving from my ol’ stable NU 5.5 & 10.6.8.
As well, very tough to even find a 10.9 upgrade option. It’s 10.11 on nothing it seems.

Nuendo 7 is tempting but at $450 !? …the upgrade costs are to me, significant when considering I do my best to simply use the DAW as a glorified 16-24 track.

Literally the only reason I’m tormented is my desire to get the UAD BX20.
Wiping the drive, re-loading all SW post OS upgrade…maybe it sounds lazy but It a hellish proposition for me.

Any other stubborn / on a budget 5.5-6 folk? …are your reasons much different?