If you're looking for a top of the line pro model best rowing machine, our recommendation for 2018 is the Concept2 Model D Indoor Rowing Machine with PM5. (aimworkout.com)
Alternatively, most gyms provide indoor rowing machines. (bbc.co.uk)
The Concept 2 Model E indoor rowing machine is the one which is more expensive and this review deals with the features and information of the same rowing machine only. (aimworkout.com)