Don't have any experience with the company but if your an alright skier you should be able to get your qualifications yourself without the full 10 weeks. Although if you have the money go for it!
Another thing to look at is which qualification is most useful for where you want to teach later on. I've looked into the rules and such for different countries but just got confused. I have done my BASI 1 and will do my Level 2 when money allows. To really make it as an instructor you need to be looking at getting the ISIA (Level 3) which is made up of around 6 modules. This will allow you to teach internationally.