I did my test and seriously, the 1st stage was not hard at all. I was suprised that so many people failed it (probably just over half). I accidentally forgot to answer 1 question and then they said pencils down before I decided on an answer so the pass mark must be lower than 100%.
Most of the answers were in the test material, apart from a few basic maths and geography questions which, tbh, weren't hard given the range of answers. Some were even common sense questions. I only read the material a few times and the answers generally jumped out at me, you didn't need to memorise it at all. And tbh, they are probably looking for candidates who are able to deal with slightly unfamiliar situations and make good judgments than ones who can only memorise a load of facts.
On the other tests I answered 43/50 diagrams and only 32/40 cubes, got a bit muddled between some questions which slowed me down. Think I got 95% of the diagrams I answered correct which were alright but maybe only 80-85% of the cubes. Judging by others here I don't think I answered enough so will probably fail, but oh well, was a fun experience.
As for travel expenses, they make it pretty clear that you only get reimbursed for stage 3. And it says on their website that only 3% of applicants get places, so you know you are gambling you money a bit if you are spending £200 getting there.