Seems like a good deal and close to the expired JB deal in terms of total cancellation fee
Total cancellation cost:
4 months worth of monthly plan fees: $69 x 4 = $276
Upfront device cost: $69
Maximum plan cancellation fee after 120 days: $690
Total: $276 + $69 + $690 = $1,035
In here for the cancellation comments that's already been quoted by OP