Yes, you can sell your properties cheap.
No, you can't do this when you are resolving payment for the space you landed on.
From Can you force property onto players in Monopoly
The only time a sale cannot take place is if a player will be cheated.
For example, Player A lands on Boardwalk with hotels and owes $2,000
to Player B. Player A cannot raise enough cash or make a trade with
Player B, so he is effectively bankrupt and should turn over all
assets. Player A would not be able to make a deal with Player C to
sell some properties for less than their value (say the red properties
for $1) since that would cheat Player B. He could sell them for more
than their purchase value, however.