Hi there. Good subject! I have tried many different shoes over the years and have learnt to stick with what works for me: regardless of price/fashion/brand etc.
I love Hush Puppies Classic Walker. Cost around $109 delivered (free) from ebay and they last a good 6-8 months of hard walking. They easily have room for orthotics which I have to also wear (thanks to plantar fasciitis from walking!). Brilliant! I just order online (now I have been fitted and know the size I want) and they get shipped to my door - no hassle!! Good luck: consider seeing a podiatrist for orthotics also to help prevent foot problems in the future due to the nature of the job.
http://www.hushpuppies.com.au/classic-walker-58.html