So my friend told me St. Augustine is the lowest maintenance grass. Here are the benefits of it

1. Green all year round
2. Do not need a lot of water, once a week in the summer, fall and spring and none in the winter
3. Kill all weed and crab grass since it's growing horizontally and not vertically
4. I don't need to remove all my existing Bermuda grass, I only need to plant seeds on top of it and in 6 months, it will take over everything, good grass, weed and crab grass
5. last but not least, it looks nice

Here's the cons

1. It's expensive so my friend suggested using seeds instead of sod
2. When you mow the grass, it needs some kind of special blade so it will pull the grass up and not cut across since St. Augustine grows horizontally. I don't really know what this special blade is.

Is my friend correct? He suggested the big size St. Augustine grass. Not sure if there's a name for it. If there's any additional cons or pros to St Augustine please let me know. Thanks

NO he's not! St. Augustine goes dormant and turns brown in the Winter.

While there are some warm-season grasses that can be propagated with seed like, all centipedes, some bermudagrasses and some zoysiagrasses, St. Augustine is not one of them. St. Augustinegrass can only be installed in a vegetative fashion: either by laying sod or planting plugs.

Sod only costs a little and is worth the money. Augustine, sells by the pallet for $185 to $225. At 450 square feet per pallet, this cost equates to about $0.35 per square foot. Floratam St. Augustine does well in full sunlight and a variety of soil types and is the most disease resistant. You want to avoid Sapphire, Palmetto and Bitter-Blue St. Augustine because of disease's like fungus's.

Just use a mulching lawn mower with a mulching blade that comes with standard mowers. No special blade.

From your zone I'm thinking you live in LA/Orange/San Diego county.
Probably the best grass for those areas is hybrid Bermuda- needs less water, fert, and mowing than anything else. I was at UCR this last Sept for a turfgrass field day and their 'dry-down' demonstration plots were real eye-openers. They stopped watering completely on June 18th and the only plots that looked OK were all hybrid Bermuda, even the buffalograss was brown. They weren't the most beautiful plots of grass but most had 30% green and a few were better- looking than some of my neighbors. When not watered, hybrid Bermuda slows waaaaay down and doesn't need much mowing and of course no fert. For the best look a reel mower is the way to go, but some rotaries will do OK. If you don't want to go to all the trouble of establishing a hybrid Bermuda, then you can pump-up the common Bermuda with water and fert in the spring, lay it on at the highest rate the package recommends and water 2-3 times a week starting in March and make sure the mower is ready to go!!

I agree with @oneeyeluke! St. Augustine is a buffalo turf with flat tips. It is suitable for warm and coastal regions. According to my experience, it is a high maintenance grass. If you are searching for a low maintenance grass, you can go for the following options -
>Bermuda grass
>Bahia grass
>Fescues
>Zoysia grass

We know that you live in California, but we don't know your soil type, or the amount of precipitation you receive in your yard... or... why anyone in California would ever chose to grow turf!

Jamesnell mentions Bahia... and... it will grow in dry sand... with zero additional water, or nutrients... but, it is still grass... no pretty flowers, and you can't eat it....

Anyone that recommends bermuda... probably should mention that it kills livestock... remember those cattle in Texas?

Fescue? Isn't that a cool season grass? probably not a good choice for zone 10.