There are A LOT of lower-priced cars that do well on the track.
BRZ/GR86 are actually advertised as purposefully built track cars, and the whole drama around this issue is because they advertised them that way, and people were eager to get something small, RWD, and "track ready," unlike, let's say, a Miata, which is most popular cheap car on track.
I meant brand new cars (was comparing brand new vs. brand new). If you are looking for used, yes, many options are available.