Princeton's WordNet

1. cheap, inexpensive(adj)

   relatively low in price or charging low prices

   Synonyms:
   flashy, chintzy, trashy, inexpensive, chinchy, meretricious, tacky, gimcrack, loud, garish, tinny, bum, cheap, crummy, cheesy, sleazy, tawdry, flash, tatty, gaudy, brassy, punk

   Antonyms:
   expensive, costly, high-priced, pricey, superior, pricy, dearly-won, generous, big-ticket(a), dear(p), overpriced, high-ticket(a), tasteful

2. brassy, cheap, flash, flashy, garish, gaudy, gimcrack, loud, meretricious, tacky, tatty, tawdry, trashy(adj)

   tastelessly showy

   Synonyms:
   forte, crummy, brazen, brazen-faced, chintzy, ratty, audacious, specious, loud, punk, shabby, flashy, meretricious, jazzy, cheapjack, bodacious, inexpensive, tinny, bum, cheap, sleazy, trashy, brassy, insolent, gaudy, garish, tatty, shoddy, sporty, cheesy, tawdry, brasslike, moth-eaten, bald-faced, barefaced, gimcrack, chinchy, flash, showy, tacky, gilded, rubbishy

   Antonyms:
   generous, costly, big-ticket(a), dear(p), high-priced, expensive, tasteful, overpriced, high-ticket(a), dearly-won, superior, pricy, pricey

3. bum, cheap, cheesy, chintzy, crummy, punk, sleazy, tinny(adj)

   of very poor quality; flimsy

   Synonyms:
   seamy, flashy, chintzy, garish, inexpensive, trashy, chinchy, meretricious, tacky, gimcrack, squalid, loud, seedy, flash, brassy, cheap, crummy, sleazy, cheesy, gaudy, tawdry, bum, tinny, tatty, sordid, punk

   Antonyms:
   superior, costly, pricy, high-priced, expensive, generous, pricey, dearly-won, high-ticket(a), dear(p), overpriced, tasteful, big-ticket(a)

4. cheap, chinchy, chintzy(adj)

   embarrassingly stingy

   Synonyms:
   flashy, chintzy, trashy, inexpensive, chinchy, meretricious, tacky, gimcrack, loud, garish, tinny, bum, cheap, crummy, cheesy, sleazy, tawdry, flash, tatty, gaudy, brassy, punk

   Antonyms:
   superior, overpriced, pricey, high-priced, big-ticket(a), generous, high-ticket(a), expensive, pricy, dearly-won, tasteful, costly, dear(p)