Your question would have a different answer depending on where in Costa Mesa you are looking to rent. On the Westside, you can probably find a 2 bedroom apartment starting around $1,200/month. On the Eastside, they start out at about $1500/month. Deposits are usually equivalent to 1 months rent, although some of the big complexes will take less.
I have to agree with some of the other posts- craigslist or westsiderentals.com will give you the best selection of rentals. Two bedrooms are generally between $1200-1500/month. I would stay away from any situation where you think a distressed homeowner might be foreclosed on though; a foreclosure that you are renting might get you out on the street again looking for a new place to rent.
It's a good time to buy- if you have the right mix of credentials, loans are fairly straightforward and interest rates are in the high 4% range right now, which is really affordable for most condos in Costa Mesa.
Broker, Veranda Homes
I do handle rentals for my clients as well as foreclosures and short sales. I try and help with everything right now as I know people are in great distress. You can look for rentals on my website, by creating a search with the areas your interested in. If you need advice on foreclosure or short sales, write me an email or give me a call.