I'm not sure about friendliness or unfriendliness to newbies but some more thoughts on the cost issue.
Some feedback that I've received through pirates and non-pirate triathletes is that it's not that much cheaper in the UK than abroad. Some hotels in the UK are much more expensive than some abroad. Although there are no flights involved, the price differentials may not be all that you think they are.
The other feedback I received is that people want to do the IM abroad and they are prepared to save the money to go there. The reasons for this are several but they include a higher likelihood of good weather (whereas the weather here is much more likely to be crappy) and also that this is their holiday, they won't have two weeks Turkey, so they want to go somewhere a bit warmer to experience somewhere different, this is the only holiday they will get. Finally, triathlon is expensive and most of the people who do it (especially long distance) know that, and they are prepared to pay those costs. Some are prepared to race less frequently in order to get the location.
I'm not entirely convinced that price/locality are the big issue that others may think they are.