SinglesCruise.com has a 3-nt "ENSENADA" Singles Cruise - sponsored by Catholic Singles Network Aboard Carnival's "Fun Ship--Ecstasy." Dates 11/08/02 - 11/11/02, Departs from Los Angeles. Prices starting at $350, plus $119 port taxes per person.
I agree, the Ecstasy is the party ship, for the Los Angeles area! Every weekend, is good for singles, really. Don't forget your sunglasses, you'll need them in your cabin, with that orange color scheme, lol. But it's fun, and the food is good, and the price is good.
There is a Jan 6th sailing from LA to Valpriso on one of HAL's ships. It will be for 14 days and cabins start about 1699$. Do not know whether it will be good for singles or if it falls within your budget.