If you have the 16th edition BS7671-2001 then you only need to take the one day course...
If they have level 3 at 2330 they only need take the 2382-20 day course too.
The one-day (we deliver it over two days, at the same price) is, I believe, an inferior option and, as I said, an error on the part of City & Guilds. Few electricians understand the regulations and an 'update' to more stuff they don't understand hardly makes any sense.
The 2382 course and exam are there to help guide you around the BS7671:2008 book. At best some knowledge will stick as it should, but after that all the exam proves is you know how to flick through the big red book and find relevant requirements.
A pertinent comment. If you do a three-day course, this is a likely outcome. We deliver the 2382-10 over
five days (at the same price others charge for three days) and we work the students hard. It's not about passing exams, it's about learning.
To give you an idea, unlike most centres we deliver eight hours actual contact per day (that's 8-5, with two short breaks and a 30-minute lunch) and set homework, which is examined the next day. Contract this with a typical course, starting around nine-ish, having ill-defined breaks, an hour for lunch and finishing by four over three days.
As I suggested, speak to the trainers and find out what you actually get for your money. Malc's advice about funding is very sound - there is a lot of money available for training, but you may need to jump through hoops to get it. Persevere though - a free course has to be a good thing, eh?