Interesting topic. From my short time (2 months) diving into RE investing and BP I personally wouldn't hire an agency or a "guru". Watching probably over 100 podcasts by now it seems the majority of successful investors are against this practice as well. BP is a HUGE resource and I'm certain you could find anything you need or want on here by networking; and the best part, it's all free. The members of BP are extremely knowledgeable and helpful, post the deal on here and get their opinion, don't hire an agency.
I do always like to understand both sides of the argument though. IF this agency knew the area or market you were referring to, maybe they were right, it's not a deal that fits their scope of work. Doesn't mean the deal can't work for you. Hope that helps.