I don't know that I would go for the cheap test with an inexperienced tester if I was trying to evaluate a kid who I suspected might be 2E - ideally, you'd want an evaluation with someone who had lots of experience with this particular population. The quality of tester observation during the test is something that is incredibly important, and frankly, I wouldn't trust a grad student to recognize "red flags" for some 2E issues, such as the fact my kid was holding his head in a slightly odd position on all of the visual subtests, or that his response times on social comprehension questions were significantly slower than on questions relating to object relationships or factual knowledge.
The money you save now might be more than canceled out by the need to do an additional workup with an experienced evaluator later to get better answers to the question of what is really going on with your kid.
