Use any of these rules to spice up your game
Cubes as rewards for advice from other players
If you are having a hard time forming a word, reveal your hand and say that you're offering a bounty in exchange for some help. Other players can now suggest words for you to use.
If you use a word that someone suggested, the player who suggested the word receives a cube from supply. Players may cash in a cube on their turn for +1c.
This rule can also be played with a turn timer, where the player must reveal his hand and offer a bounty when the time is up.
Discard hand for a cube
If you can't or don't want to buy a letter, you can discard your hand (not forming a word), and gain a cube from supply. You may cash in a cube on you turn for +1c.
Cubes as discount tokens
When a card is purchased off the top of a pile in the Offer, that pile's corresponding alternate card gets a token. For each token on top of the alternate card, its price is reduced by 1c (can't reduce price below Oc).
Remove the tokens when the alternate card is purchased.
Recycle the 2c cards
If the 2C pile runs out, take all the 2C cards in the trash and shuffle them and re-create the 2c pile.