If you belong to any credit union, you can get the 10% off discount. There are university discounts too. But I just realized in your price comparison you were looking at the normal Everything Data plan (450 mins/$70 per month).
If you don't qualify for any of the 15% or higher corp/school discounts, you might want to go for the Everything Plus Data plan instead (500 mins/$60 per month). When I called to convert my SERO account to an Everything Data plan, the rep automatically assumed I wanted to convert to the Everything Plus version without me even having to ask. I don't think you can stack other discounts on that plan though.
If you don't qualify for any of the 15% or higher corp/school discounts, you might want to go for the Everything Plus Data plan instead (500 mins/$60 per month). When I called to convert my SERO account to an Everything Data plan, the rep automatically assumed I wanted to convert to the Everything Plus version without me even having to ask. I don't think you can stack other discounts on that plan though.