Unfortunately, the market is down because Greece wants out of the Eurozone. 

Am not an expert on this but here are possible first steps:;Dont just drive by, When you see potential candiate property, stop and ask questions from the neighbours, search the net for the last transaction on the property, visit the county office for available city records..etc.

(ex. plumbing, a leaky roof, noisy neighbour).

I'd also post no trespassing signs and talk to the neighbours. 

@Dean letfus BRRRR strategy is difficult to put on in New Zealand but is it same in neighbouring country Australia as well?

A phone call from a neighbour ranks right up there.

I've been walking and driving for dollars in a few neighbouring cities, and identified some addresses I think could be deal prospects.

Tell the neighbours to call the police and report the problem. 

Rental permits in Greece, any info?

Tell him it is great that his company has grown, but he's also outgrown the space and more importantly the vans are blocking the tenants cars in AND they are disturbing the tenants and neighbours with the early morning coming and going and chatting.