To ride up to a 125cc you need CBT, which is normally I believe about £100.
I'm not certain enough about any other specifics to give any good pointers.
You'll need a CBT to ride upto a 125 with L plates. and that is valid for 2 years. Tax should be about£35 or slightly less as thats what it was for my motorbike. You need a helmet, jacket and gloves minimum, protective trousers are a very good idea. The helmet can be from £45, gloves about £30, jacket about £50 and trousers from £20 which are waterproof and with armour .
My bike was £700 not brand new, but was a 400cc engine (i had to get it restricted) you should be able to get a 125cc for about £500.
there cant be many bikes that are bigger than 2m long or 1m wide so your probably safe there!
Tax will be £15 for a 125cc.
Make sure you spend a bit more on helmet. I'd recommend no less than £100.
I would recommend you wear ATGATT (All The Gear, All The Time): that means Helmet, Gloves, Jacket, Boots. Trousers are optional for scoots imo.
A scooter is very cost-effective. You're looking at about £20 a tank at around 50mpg, with room for shopping in under-seat storage and unbeatable manoeuvrability in the city. Go for it!
Trousers are optional, so long as your wearing jeans, coming off at 30mph isnt fun in work trousers. And they are a plus in the rain.
Both me a my bf have come off in £45 helmets and not have any problems, but we did both get cheaper ones for the first year and we were both told that we would be likely to come off in that time. He managed to come off in 2 weeks after passing his motorbike test.
His helmet is now £150 mine is a £45 reduced from £120
You can get a cheaper helmet, as long as it has a gold sticker on the back. This means it's approved by the AdV (I think) and it'll provide the best protection in a crash.
Jeans really don't offer any protection at high speed if you're thinking about commuting on open roads. In my worst crash (60mph off into a telephone pole) my jeans shredded to nothing in about three seconds of road sliding and left some lovely burn marks, but this isn't likely on a commute-a-scoot. I wear Draggin Jeans these days, which cost about £100 and look and feel like normal jeans. The difference is they're made of kevlar and have spaces for CE inserts.
Nice video, but I'd take it down/edit it, I've heard stories of people actually being prosecuted with their own evidence!
Edit: Never mind, it's a dual carriageway.