These two are hard to find at the moment, I'd have thought there'd be loads on interest.
For R5, a graded one with a 50 bubble went for £400 or so at Vectis, and a plum mint one £1350 or so after fees, can't remember whether last years sales on here had an R5? You can't tell what the bubble damage was on the graded one, but for a 50 it must've been quite severe. It may have been been overhanging off the bottom of the card, not sure. As the one on here has (probably) less damage I think £600 - £750 estimate would be pretty good. The higher end depending on the bubble.
For Ben, plum mint ones are £2k - £3k, higher end with Vectis fees, lower end without. Some did go on here for mid £2k and didn't hang around iirc. I think £1000 - £1200 is reasonable, but could be a bit more as it's sought after.