I heard that fees for listing altcoin is too expensive even in small exchange site.

Take a look at this article hereThe Cost to Get Listed on a Crypto Exchange

According to the article the listing fee is around $6,000-$30,000 for small exchange and $60,000-$300,000 for medium size exchange and for big exchanges the fees is too expensive.
I don't know if this is accurate but I believe that there are some exchanges with lesser fee.