If you don't intend to do bicolor parts, the only 2 questions are : will you require soluble supports ? Do you need to save time to the point of having different heads for faster infill ? If not absolutely necessary, save some bucks.

It does make the levelling slightly more complex. But I'd like to say this : the secondary head is problematic only when in use. When you use the 2 heads in a print, it helps to turn off the one you don't use.

If you like to be redundant, a second head can ensure you work when one is down.

I don't regret buying my printrbot Metal Plus Dual, very good & reliable. I don't use the second head that often.