96 jimmy tranny problem

hello there, i have a 96 jimmy that the tranny went out slowing...it started with loose of power. I would step on the gas and bareling move and now it wouldnt do anything. the vehicle would go forward slow in any gear. it the transmission gone and is it expensive to fix? thank you

From here how can we diagnose this, sounds like a trans or a severe loss of engine power, have it checked out, no?