Good Electric Strikes are not cheap. Yes, you can buy one for 30 - 50 dollars but in the end, you might not like it. Remember here is definitely: You Get What You Paid For It. So think twice before you drop your bucks on some cheap imported crap!
A Von Duprin is a heavy-duty strike with a 24-volt AC or DC coil.
The cool part about this strike is that it has a Dual switch monitoring option that has two SPDT contacts, one switch monitors the tripper which is depressed when the latch bolt is inserted into the strike pocket. The second switch monitors the condition of the strike lip, open or closed and locked.
Now to warn you this is the big dog on the block at over 400 dollars, but they have others for about 100 bucks as well with monitoring.
Their less expensive strikes you can find for 100 and 200 dollars. You can see the difference in construction between the two of them. I think I would spend the extra money on my outside doors.