Chris, yes the food/drink prices are typical NHRA. But there is no parking price-gouging like at so many other tracks. At HPT, parking is free. It is a good walk from parking lots to seats. If you want General Admission seating, it is also a long walk to the pits as GA is all on the west side, the pits on the east side. Definitely bring your most comfy shoes.
If you want the closest seats to the action, sit in V.I.P. reserved rows 1-3. You are angled looking down the track right by the burnout box and (usually) don't have a lot of people standing to block your view.
If you want the closest seats to the pits, sit in 'Pit Side Reserved'. These seats are at about the 700 foot mark on the track. The main pit areas are right behind you.
Don't forget sunscreen. The new HPT ownership is planting trees and building shaded picnic areas, but the high sun in June in Kansas can be as brutal as Bandimere at 5800 feet.
Restaurants-Pat's Pig just north of HPT a couple miles on Topeka Blvd is a true racers hangout. Nothing fancy but great Bar-B-Q and sightings of H. Will's team, R. Capps team, T.Johnson Jr's team, the Safety Safari etc etc are common especially early in the weekend.
Lots of other restaurants out at I-470 and Wannamaker, lots of motels in this area too. Topeka does book solid in advance of the Nationals being a smaller town, so get your room(s) early.
Hope this helps!