Ford Repair: 2003 Ford Focus ZX5 auto. trans. repair, trans repair, slow car

Question
Tony,
Had the car since new. 70K miles now. Just started noticing the transmission slipping going from gear to gear - revs, then goes into the next gear (not all the time though). When passing a slow car and I step on the gas pedal, the car may "thump" before taking off too (again, not all the time). I know somethings up with the trans., from what I've described is it serious enough to take to a mechanic now, or can I wait? What should be an approximate cost to repair?
Thanks,
Jimmy
N.J.

Answer
Hello Jimmy, Yes what you are describing it does sound severe, it is not a good idea to wait to long. The cost will determine on what is wrong with it from what your diagnostics will show. Need to start with diagnostics 1st and go from there. Thanks Tony