If you like group play, then yes. For as singleplayer I wouldn't recommend it. I personally have more fun watching the bot grind then doing it solo by myself.
You should also have some starting gold for equipment, otherwise you won't get happy. If you reach Level 60 you should have at most 1 million. "Good" Equip (means you can farm Inferno, an area wich can be entried at lvl 60) it should be at least 50m to make it worth the energy for botting AND a bit of fun to play. Some people will disagree to that 50m, but this is my opinion. Fun started for my when I had equip for about 300m.
You normally can't rely on drops, especially with good gear. It will most likely look like a "wow green equip" to vanilla / pre-vanilla (beta) times. Inferno with monster power 1 or higher would be comparable with a heroic dungeon in wow. But alone not as a group.
The price for diablo3 would be 34,85? on IneXus.us btw (lowest I found).
If you enjoyed plaing Diablo2, then Diablo3 could be viable for you. If you just soloplay and did not play d2.. your decision.
Sorry for my bad english, it's not my native.