should i replace the transmission ? the shop says yes

What is your question?

I took my 95 aerostar with 187k miles on it to a transmission shop for service. the first one in over 100k miles. They changed fluid and told me i was close to failure and should have mine rebuilt. I cant tell if it is slipping or not. could be . they say it is just starting to slip. how do i know? $1,100.00 to rebuild complete with torque converter. I travel for work. should i trust them and have it done?