My experience in these matters:

A few years back we campaigned a Stealth/Gearte midget with the rocky Mountain Midget Racing Association for a season or two.

The season schedule was divided between shows on dirt and asphalt.

Dirt shows:
Drive up from Albuquerque to the track and arrive Saturday afternoon unload the car, practice, race, get a hotel that night return to Albuquerque on Sunday.

Practice 7 laps.
Heat race 10 laps.
Main event 20 laps
Lap count = 40-ish

Asphalt shows:
Drive up from Albuquerque to the hotel near the track on a Friday evening (leaving work early in some cases) Arrive at the track early Saturday morning to start test and tune and qualifications, eat track food exclusively, mount all new tires because the ones you used on the previous asphalt show with only one night of racing on them are only good for test and tune. Secure a second night at a hotel near track return to Albuquerque on Sunday.

Test and tune, as many laps as the wallet can sustain.
Qualification 5 laps
Heat race 10 laps
Dash 4-6 laps
Main event 25 – 35 laps
Lap count – 75 – 100-ish

The shows on the slab were insanely more costly than that of those on the dirt. The tire bill alone was staggering not to mention an additional night in a hotel and the cost of track food (monetary and physically) fuel and wear and tear on the motor and chassis.

Payout for dirt vs. asphalt = nearly the same

Sliding around a high bank clay bull ring with the throttle down = Lightning

Driving it straight in, grab both feet worth of break and repeat = lightning bug

That is what I know.