you can breed electabuzz and magmar for as many baby, there is no limit (until you run out of room in party and pc), but you can only get a electabuzz at lvl 30 because magby, smoochum and elekid evolves at lvl 30.
^ In other words, no. You can't. When breeding you always get the lowest form of the female (or when using Ditto, the Pokemon that isn't Ditto), so you'll get Elekid and Magby every time.
The exceptions are Marill and Wobbuffet. You will get these Pokemon when breeding unless you use the Sea and Lax Incense, respectively. Then you will get Azurill/Wynaut.