I'm not sure about the value of my e30, it's quite high due to the spec - it has good suspension/arbs, lsd, the 2.1 engine with forged bits, arp rod bolts, lightened fly, mls h/g, flowed head, catcams, standalone mgmt, big bore tb, lpg, cruise etc and is quite clean.
An mx5 (miata) mk1 would cost less, a mk2 would cost about the same. If the right BBR turbo turned up I would jump at it. The plan would probably be to get a mk1 miata and an e46 318 on lpg as a dd. My e30 is much more powerful and faster in a straight line than the mazda, but on the twisties they're a lot of fun! I remember chatting at the ring to a few people about some of the times that people can do in miatas, I think it would take a seriously good e30 to match them. I've always loved the handling and the 'feel' of the miata when i've driven one, but whenever I've been on track the only cars present have been a good deal slower than my e30. Though a lot of that may be down to the driver, I think with such a momentum car (low power) you really need to be committed to make the most out of them.
I'm not sure about it all really, I've had the e30 for a long time and it is a good do-it-all car. It's quite well mannered as a dd, and quite good on track. It's not perfect at either though - it needs less weight, more grip, better brakes, stiffer suspension for the track, yet needs a better idle and a better map, more sound deadening and less noise to be perfect on the road. That's why two cars appeals -the e46 would be quieter, more comfortable, better on fuel etc as a daily, and a mazda could run a serious track setup. I was very impressed with my friend's vx220 (opel speedster) at the nordschliefe.
Is just a thought at the moment.
The idea of keeping the e30 as a track car and getting another dd did cross my mind, it would be a sad way to treat it though i think as it's in good condition, and ultimately the e30 is fairly heavy and a miata would probably make a better base for a track weapon.