Yeah the clam replacement/repair is always a concern, although I get more concerned with significant off if there is damage to the front suspension pickups. You can replace/repair clams easy enough, front crash structure and rear subframe is easy as well but the front pickups are part of the chassis. If you get a bad enough off on track every car you consider can rack up repair costs very quick.
When looking for trackable cars I care more about consumable costs and replacing the bigger ticket mechanical items (transmission/engine) than I do the body parts.
I prefer light cars for this reason so the Elige fits perfectly for me. If it wasn't the Elige, would be looking at NC/ND Miata, BRZ/GR86 as my options. Once you start looking beyond that the run costs start increasing.
If you can wrench your own car the lotus is so easy to work on, everything is inexpensive to replace (apart from body work/full chassis). I think over 10 years and 6k+ track miles the only mechanical failures I have had so far have been 1) OEM clutch torque strap 2) ACT clutch spring 3) 3rd gear @ 50k miles. I have also had to replace the clutch release bearing every 2-3 track seasons.
Beyond that the tires are small size/inexpensive, brakes last a considerable time, and then just replace parts as they wear.