Bottom line is, it's a preference call. The e30 is as awsome as you deem it to be. If you like how the trailing arm setup works, then it's the car for you.
It's nowhere near as easy as it is building up a 240sx. The hardest part to deal with is coming from a 240's aftermarket support and go to an e30's aftermarket support. Parts are available for reasonable prices, and they cost a bit just like many 240sx parts... people dont take that into consideration because in the drifting community, fixing a problem means buying a used part in the junkyard. By those standards then it costs the same, but many BMW guys usually rather spend the extra dollars to buy a replacement part new.
Now there are ways to go about it... there are many OEM parts distributors that sell quality parts for cheap. Usually there are those who are so short sighted they make the mistake of going to the dealer for prices.
As for models, there have been those who managed to drift even the 325e's and their 4,500rpm. But you'll quickly find yourself limited in what you could do with them. Antti drifted his with a 5,500rpm and with a quick ratio diff, he used to drift in 4th and 5th gear to find power.
There are many models that you can get upgrades from at the junkyard, just like the 240sx.
In the end.. there are those who will love the e30 and there are those who will hate it. If you like ass happy and you want to practice precise steering control and get good with snap oversteer situations, then the e30 is the right car for you. It's challenging, but personally I feel like it's a blast of a challenge the whole time.
- Erick