I started playing BoB because I thought it was a fantastic game for "squad" level actions for ancients/dark ages etc, because the close combat rules are great ( there are a few more in BoB vs Scrappers ).
To me the biggest leap of faith was testing it for moderns and seeing that it reslly worked great for that, which it does.
You are starting with Scrappers, so if you like it, then you can only gain from getting BoB ( which goes for less than 10$ in lulu). The periods feel different enough that they are fun to actually use the same rules for all of them, and then with one standard set of mechanics you can have tons of replayability...
Hope you enjoy the game as much as I do..
cheers
Francisco