can you buy a personal blood pressure machine that you can have at home?

Yes, it is very possible to buy an "at home" Blood Pressure Machine. I actually have low blood pressure, so my Doctor requires that I have one at home to take my blood pressure on a daily basis. Depending on the brand, they usually range between $50-$100.

The LifeSource UA-789AC Extra Large Blood Pressure Monitor offers an extra large digital display and large buttons for easy operation as well as Irregular Heartbeat Detection, which provides blood pressure and pulse rate measurements even when an Irregular Heartbeat occurs, and HeartWise Technology which measures blood pressure on inflation while filtering out ambient noise on deflation. WrisTech Wristband Blood Pressure Monitor is Easy to Use! Typical Blood Pressure monitors are big, bulky, and nearly impossible to use without assistance. The WrisTech Wristband Blood Pressure Monitor is compact and lightweight and easy to use even by yourself!  This Microlife Premium Portable Blood Pressure Monitor is the convenient way to keep track of blood pressure readings even when you're traveling. Just one touch is all it takes to get your systolic, diastolic and pulse readings, as well as irregular heartbeat detection. 

The Lumiscope 1103 offers 85 memory recall at a super-low price! Semi-automatic operation - manual inflation with auto deflation and measurement.