Going once, going twice, SOLD ... is what some lucky bidder will hear if they win a date with Octomom ... because the mother of 14 has officially put herself up for auction to earn some cold, hard cash.

Octo -- in a last ditch effort to earn more money before she gets kicked out of her La Habra home -- has created an online dating profile for a site called What'sYourPrice.com ... a website where users can PAY other users to go out with them.

In her profile, Octo says she has 14 kids, loves to work out and loves to laugh ... and she's starting the bidding at a cool $500.

This is the latest in a slew of ploys to earn more green off her Octo fame. If you recall she also signed up for a website where she can beg her fans for money ... but so far she's only raked in a mere $2,509.

... which is $2,509 too much.