>>511787PLB's do not require a service plan/fee.
SPOT/InReach do.
To my knowledge, there is *no* single PLB/SatComm/GPS all-in-one unit.
The closest you'll get is DeLorme's InReach system - there's a SPOT-size pendant with a few buttons on it, that communicates to a GPS receiver (or smartphone) and gets you some additional features with the two paired up.
PLB is an emergency-only system. Carry it hoping you never need it. No tracking, no twittering, no bluetooth, no bullshit.
If you (or your family/friends/whatever) wants tracking/help/OK-messages, a SPOT/InReach might be your best bet (I'd go with InReach, iridium constellation's a bit more reliable than globalstar that SPOT uses).
SPOT/InReach/PLB's all use a GPS receiver to pinpoint the device's position and relay it through whatever channel the device uses. They do *not* function like a GPS receiver, and cannot be used as one.
I'd look for a used SPOT or InReach unit and pay for a couple month's service while you're out, but $100 is a pretty tight budget for that sort of equipment (not saying it's not doable, just ... you're gonna have to look hard).
