I wouldn't hesitate to buy another RX-8. Either an R3 for track/weekend purpose, or mod the current car for that purpose. I've spend over 14hrs in the 8 (driving to & back), and found it to be very comfortable. It is almost luxury sedan like on the highway.
I overlook all the minor so-call flaws in the 8, enjoy it as what it is and has to offer. Also owned an 90 BMW E30 325ix, with close to 300,000Km on the ode, it is also a high maintenance, with its age and mileage. But geewizzz, there is not too many cars like it on ice/snow/gravel, well worth the time and effort.
Spend under $20,000 on the 8 total (include initial purchase) so far in the last years, and only fluids changes are needed. Our first CX-7 was leased for 3 years, and the lease payment in that time were over $24,000. I can see the value and better return on the dollar with the RX-8.