In Marina Del Rey you get more bang for your buck vs. Santa Monica, Pacific Palisades and Brentwood. This means you can get a larger townhome or condo. Single family residences are fewer and far between but do exist there and are cheaper than houses you would find in Santa Monica and Venice. 

Given that MDR is just 2.4 miles from the beach and has a lot of shopping and dining it's a great alternative to Santa Monica and Venice.