Daniel,
I couldn't locate a lower price than the $229 advertised. I would go with the AAA rate unless your company is part of Cal Works or Wild@Work. They have discounted rates for those two groups using the LPR promotional code.
Does it have to be at that property? There is another Marriott which should be near that one. This is the San Diego Marriott Gaslamp Quarter and for this property, I see a possible LNF rate that you might be able to claim. Check your PM shortly with details if you're interested.