Omelet

hi. i want to start riding. i really think that its a sport i could get into to. i dont want to spend much on a bike until i know im into it. ive been searching for a dirt cheap road bike, and in fact i almost bought a first price, very basic, tiny bit too small, road bike today from a sports store. however, the sales guy said that he would strongly suggest that i not buy i road bike if i am not acostumed to riding one. instead he wanted me to buy an 'all purpose', 35+ lb, bike - saying that a road bike would make my back hurt too much and that the back pain would discourage me from riding. i told him i wanted something i could use to ride with my local road club and he said that the all purpose bike was the best bet for a beginner. i didnt like his answer very much. was he right? if im new to the sport should i start with an all purpose?