i made my curly girl products as frugal (frugal, not cheap) as possible with one exception, so here's my list:
suave essentials coconut conditioner as my co-wash. wal*mart used to have a 30oz bottle for $2 in stores, but that price went up like everything else. :/
tresemme botanique conditioner. for some reason, the renpure factory isn't producing the argan conditioner right now, otherwise i'd use that; tresemme botanique is my next best frugal option.
shea moisture leave-in conditioner.
and the not-so-frugal aunt jacky's coconut hair gel. the most frugal gel option is the la looks mega hold yellow gel, but i prefer the scent of aunt jacky's, even though functionally there's no difference between the two products.
not a necessary curly girl product, but i 110% recommend this scalp exfoliator for all hair types. it takes more patience using this tool than just using your hands, but your scalp will feel lusciously clean after use.
a satin bonnet for sleeping in.
some professional-level scissors for cutting hair. use with tremendous restraint and trim with caution.
dollar tree has this wide-toothed comb for $1.25 if you need a new, simple comb for detangling your hair.