2nd cheapest: plain concrete pavers from your local big-box store. For a few dollars each you can buy 12x12 or 24x24 if you can get someone to deliver or lift them for you. Don't know your zone but in my zone I put these on plain dirt, no base required, and you can lift and re-level them if the dirt settles.

KarinL

Aggravation, effort, money, labor, and maintenance is the currency. Which ones do you not want to spend and which are you willing to spend?

Pea gravel can work fine, but it has to be done right. The problem is that it takes a lot of effort and understanding to do it right. More often than not, people who do not want to invest either of those are the ones who go with pea gravel. That is what most of us see or have experienced ourselves which is why so many people say it is no good.

Poured concrete is not an expensive material, but preparing for it is often hard work and takes some knowledge to form it well. Finishing the surface is not as easy as it may look.

Watch HGTV and you might think tossing a bunch of flagstone around makes a good patio.

All of it has a price to be paid one way or another.

Here’s a few thoughts based on experience to help you choose a design and materials direction

The cheapest material to lay down for a patio is compacted class II road base.
It comes in different sizes of ‘rock sizes’. By using a small chipped rock size you can achieve a nicely finished looking patio for very little money.

I did all my paths in this material and would have done my patio with it , had it not already been installed with concrete.
In my geographic area ( one of the most expensive in the US ) it cost me $ 10.oo a yard in materials. I did the labor.

Link to photo - Stoney Point road base gravel :http://picasaweb.google.com/lh/photo/QLV2gitwkc8xrrPn1PjfGQ?feat=dire ctlink

Coming in second in regards to the raw materials is CRUSHED GRAVEL not PEA GRAVEL
The two types of gravel are extremely different in regards to price and how they work as a surface treatment.
Crushed gravel compacts down when the proper thickness is laid. The small stones are angular and compact down.
Pea gravel never compacts due to it’s round shape. It will almost always be squishy under foot unless it is mixed with a binder.

Link to a crushed gravel patio area. http://picasaweb.google.com/lh/photo/2sbKsocpCgh-6C3FFtUg9Q?feat=direc tlink

The next financial step up is recycled cracked concrete.
You can often find this raw product free but the amount of labor that it takes to lay the sub base and set the stone makes it a more costly product than crushed gravel or base rock surfaces.
Link _ http://picasaweb.google.com/lh/photo/bYLsDHN9uHuDQwR-poTVnw?feat=direc tlink

Next up Pea Gravel - I never use it for a path or patio . I find it messy, uncomfortable to walk across and aggravating to set furniture on. I don’t recommend it at all. It is a nightmare to maintain especially if you have an adjacent lawn , which makes it a down right dangerous choice.

Decomposed Granite is the next choice.
In my area this material is pretty costly in comparison to other surface choices.
Call around to the different suppliers to get price quotes.
You may find in your area that DG ( decomposed granite ) is the same price as crushed gravel or maybe even less. In my area it is significantly more costly.
It is a product that can be laid down by a DIY’er.
I strongly suggest that you have a BINDER mixed in with your D.G. to keep it from turning into mud after a rain storm.
Link to a DG patio area -http://picasaweb.google.com/lh/photo/qVRjqspD5PFAqQmixS_l-w?feat=dire ctlink

There is also a DG. like material called Terra Pave. It is basically DG mixed with a super hard biner ( Pine Tree tar ).
It renders a hard as asphalt finish and is really lovely.
We professionally install it in the N.Cal area for about $ 10.00 a sq. foot.

Concrete is an excellent long term investment for a patio surface.
It will out perform the above mentioned surfaces ten times over.
The cost upfront is more $$ but in the long run , it is more cost efficient and low in the maintenance catagory.
Link to a colored concrete patio _ http://picasaweb.google.com/lh/photo/IS4whvxcbXEB8aVQbbjrxg?feat=direc tlink

These are some of the most inexpensive surfaces for an outdoor patio.

I'm looking at DeWitt Pro-5. It's expensive and I'm wondering if their lower priced product would be good enough. They are guaranteed 20 and 15 years respectively. Dones anyone have experience with them and know if crushed gravel on top damages it?