A couple of additional comments.
I would recommend that you learn to take your own blood pressure, there is a technique to getting an accurate reading, height and support of the arm that you are using being one of them. A good device need only cost around $30 - $40 and you have it for life.
In addition when I found that controlling blood sugar and hence insulin, was the key to blood pressure control, then I invested another $30-$40 in a blood sugar monitor and strips so that I could be sure that my new found diet was indeed controlling blood sugar at the appropriate levels.
I monitored blood sugar at intervals over a 2 month period it did give me the confidence that my new food choices were indeed controlling my blood sugar / insulin levels. I am not diabetic merely insulin resistant and so I did not feel the necessity to monitor on an ongoing basis.
Dr Bernstein's clinic will freely give you advice as to which blood sugar monitor is their choice.

Good luck..