After seeing so much conjecture about the xp saved by beds, and various Raise spells at various levels, I decided to do a little testing myself this weekend.
I have always accepted the belief that Raise II only benefits someone if they are level 50 or above; but people argue about it and I wanted to make sure.
So I took a level 30 job with a 3542 xp buffer and died several times.
At level 30, your TNL is 5800 -- therefore the loss of xp with death should be 580.
My first trial: Dying and going back to my Homepoint. In my Mog House was a Noble's Bed, a Mahogany Bed, a Bronze Bed, and a Simple Bed my total xp loss was 440 (approx. 75% of 580) - The beds saved me 25%.
My second trial: Dying and going back to my Homepoint. In my Mog House was just a Noble's Bed and my total xp loss was 440 (approx. 75% of 580) - The Noble's Bed alone saved me 25%. I do not, therefore, believe the beds stack.
My third trial: Dying and getting a Raise I, while I had a Noble's Bed in my Mog House. My total xp loss was 330 (75% of 440, which is 75% of the 10% 580 I should have lost). Even not going to the Homepoint, the bed saved me an initial 25% with my death, then I received an additional 25% of the modified death penalty when I got raised. You do not need to return to Homepoint for the beds to take effect.
My fourth and final trial: Dying and getting a Raise II, while I had a Noble's Bed in my Mog House. My total xp loss was 330 (75%of 440, which is 75% of the 10% 580 I should have lost). Once again the bed saved me 25% right off the top, and Raise II added no benefit because I was under level 50, as expected.
I would like to try once more, and receive a Raise III, but I couldn't find a WHM70+ willing to help at the time. I believe Raise III give the benefit regardless of level, as I received a Raise II when I was around level 40 and got back nearly all my xp. But I would like to test it to be sure, when I have the exact xp amount written down before and after my death.
Incidentally, twice while I died I had my status window open and saw the xp drop -- with the bed(s) in place, each time it was a loss of 440. This was before I returned to Homepoint or was Raised.