You are right about the cost, but i found the time thing frustrating. Once you have the tech evaluation under your belt there is only a couple of standard setting courses per year, aswell as the training techniques course, they like you to do the lantra one of which again there are very few.
Saying that though lantra do have there benefits like the fact it is nationally recognised, all instructors are regully verified, so you know your going get a good standard. I have a top TSV and is very supportive, always there for advice when needed. There is the insurance, the cs work books are good. ( the UA ones are rubbish though)
As for the original question i could nt say now, it is expensive and time consuming but i have found as part of my business i find training and assessing very rewarding, it takes me all over the country and over to Ireland. Most of these places i probably would never have seen.
GOOD LUCK