Hi Lou,
Have not bought trips off Thomas Cook Reps as always fly with First Choice, but you can buy cheaper trips in the Playa Dorada Shopping Mall, they are exactly the same as the reps sell but as I said cheaper.
Here are a few prices that I kept from the Mall on our last trip to the Dom Rep.
Catamaran US$65 - Paradise Island US$65 -Paradise Island VIP US$80 - Ocean World US$145/100/80
We did go on Outback Safari which was great, hired our own government tour guide with taxi and went all round Puerto Plata town, Cigar Factory,Amber Museum and Rum Factory, far better than an organised trip as you can stay as long or as short as you wish.
Hope this helps,

Angie

We are off to Grand Oasis Marien in may have done some research into trips check out the trip advisor on the Marien lots of people there recomend a guy called michael cant remember the last name but it pops up everywhere also they have an email address for him so you can contact him direct hope this helps