The prices for laps around the 'ring this year were £20 for one lap, £68 for four and £130 for eight.
I'd expect they'd be pretty much the same next year also, but obv. does depend on the exchange rates.
We stayed in "Pistol Pete's" B&B, which is literally round the corner from the ring entrance and has 16 rooms (most twin, some triples).
It worked out at about £32 per person, per night for the twins, and £22 per person for the triples.
all in all, the ferry, ring and hotel cost me £190 (exc fuel and food) for a three day trip!