32kbps for the low quality stream.
64kbps for the "premium" if I'm not mistaken.
do the math:
32000 bits per second
x8 = 4000 Bytes per second
x60 = 240000 Bytes per min
x60 = 14400000 Bytes per hour
14.4 MB/hour (14.4 Megabytes per hour)
3 hours per day = 42.2MB per day
*20 days (5 work days per week/4 weeks) = 864 MB.
I think that's OK to do. I don't know what Sprint's policy is on data use, but on AT&T you're fine as longs as you're under a few Gigabytes per month.
iPhone 6 128GB on Verizon | iPad Mini 2 Retina 128GB on T-Mobile (free 200MB)