I have both a box and several angle blades. Both have been hobbies of mine, and I've owned a 3 or 4 box blades and perhaps 6 or 8 angle types. If the choice is between an inexpensive box blade and an inexpensive angle blade then go with the box. If you can spring for a real good blade with big tractor features then the blade may be more versatile.
It depends on what you do. I never do any scarifier work, so that isn't a need for me.But like I said, its a hobby for me and there is a better way. Most of my work is grading and repairing my long dirt roads....I am mostly skimming on one side and moving the dirt into ruts and widening and crowning. Something to consider is that the dirt here is very rocky. What fills the bill for me is a very heavy angle blade with tilt, angle, offset, and most importantly: the end plates. I normally run it mildly angled with the forward end cutting (no end plate) and the trailing end covered with an end plate. For my ground, this gives me all of the best abilities of the box and the angle blade.
Angle blades with those features are expensive. I think my 6 footer cost close to $800 and weighs around 500#. It is well matched to a 33 hp tractor. I tried a lighter mid-priced (350#) 7 foot blade with similar features but it just floated on the ground instead of working for me.