I've ranted about both Racketboy and price guides in the past, but I don't have any problem with games being placed in very loose tiers of value.
For the <$10 list, these games are currently available from ebay, half, amazon, or prominent online vendors for $10 or less, with a couple of exceptions of recently auctioned items (not freak BIN's) in the completed listings. I did not note their completeness as casual beginners shouldn't concern themselves with such things. I'll let you be the judge of whether they are good or bad games. Games marked with a "+" were slightly above ten: $12-13.
Alien Crush
Andre Panza
Ballistix+
Battle Royal
Bravorman+
Champions Forever Boxing+
China Warrior
Cratermaze
Cyber-Core
Davis Cup Tennis
Double Dungeons
Drop Off+
Dungeon Explorer
Fantasy Zone
Final lap Twin
Hit the Ice
Jack Nichlaus
JJ and Jeff
Keith Courage
King of Casino
Legendary Axe
Legendary Axe 2
MotoRoader
Ordyne
Pac-Land
Power Gold
Sidearms
Silent Debuggers+
Sonic Spike
Supervolley Ball
Tailspin
Takin'It to the Hoop
Tricky Kick+
TV Sports games
Victory Run
Vigilante
World Class Baseball
Yo Bro
I did not include shipping. It typically ranges from "free" to $4, but can vary widely depending on where the buyer lives and combined rates. I think it's best not to include shipping.
There are only a few U.S. CD games immediately available in the $10 range; none of them I would call good:
Addams Family
Sherlock Holmes
Magical Dinosaur Tour
IT Came from the Desert +
I would recommend including Buster Brothers, Exile, CF2, and Prince of Persia as good $10 games, but patience is required to find them at that price.