Upon first inspection the word 'nifty' springs to mind.
Second inspection not so 'nifty'.
You dont really need an air matress on a camp bed, come on,,you shouldn't be able to feel roots or stones that high off the ground and once you are in a sleeping bag it will feel comfy underneath. Air mattresses make you feel the cold if they are cheap and un-insulated, better off investing in a good thermarest mat for insulation, although, the moot, your only venue in the summer should be fine temp. wise.
The bed will cost you £30 from Argos, the tents worth that of less, Its only 1000HH although the British Army regard 850HH as waterproof, I dont. As Crosslandkelly says bit pricey if you are in the know, and you do need a tarp/cover for anything you don't want in your sleeping bag, boots,coat,clothes camp chair etc.
Its single skin, no fly sheet, cant see many airvents so your condensation factor will kick in,
If you have access to a camper van and your only worry is getting it dirty, i'd park it 2mins down the road and walk up to the moot,
Lets see now,, camper vs tent,,
van...
solid roof over you head,
central heating,
no setting up,
no hotel fees,
fully fitted kitchen,
en-suite dunny with no zips to undo at 1am,,3am,,and 5am, ,(although you probably won't find any ducks to punch in there)
all home comforts,
water-proof,
no drafts
no hanging stuff up to dry in the garage when you return,
ability to bring anything and anything,
QUIET WHEN YOU WAKE UP!
You dont wan't to spend much money,
you get up 3 times a night,
you are only camping once a year
and you don't own any camping clobber,
AND...if you are parked on private land you could have a few more tipples,
I love a bit of tenting and to be honest its more fun at the end of the day, but only because MY parents won't lend me THEIR camper van!
I'd phone yr folks tonite and book the van for next August if I were you,,LOL
ATB.