This means you are already in the business, know and understand the coffee/espresso biz, are abel to do the shop layout/design and planning yourself and just need someone to scout locations, do the paperwork etc?
If that's all the consultant would do it seems like a big chunk of money. If, on the other hand, the consultant is actually going to also come in and implement your plans but finding a contractor, superoving build-out, getting everything stocked, propsective employees screened, dealing with vendors, following through to be there for permits, inspections, approval visits etc..... $4,000 to $8,000 could be a bargain.
For me it really boils down to whether I'm paying someone for their expertise or just for their time and a reasonable level of mature judgement to act as my proxy because I'm already too busy running the first location to tackle the whole project on my time. I'd pay far more per hour for truly verifiable expert advice if I was inexperienced but personally.... I'd be hesitant to turn over a lot of the other details to a third party.