I am making one that is definitely not high-tech. I am not sure where you would buy one reasonably priced. At the plant nursery I frequent, they are pricey. Maybe Lowes or Home Depot might put them on sale now that it is winter? Click on my link below to see my cobbled together birdbath.

Here is a link that might be useful: Silva's blog

you might also try terracotta pots glued together for the bottom with the large saucer upright on top for the birdbath part and just mosaic the whole thing...or if you have a place that sells concrete statues and fountains,,they usually have some

heres a link that shows some

Here is a link that might be useful: birdbath

do look pretty easy. I think I could handle one of those. Now does anyone know a particularly cheap place to buy pots?

Just another thought: I made a concrete table using a plastic birdbath as a mold. You could just pour concrete into the stem of a plastic birdbath to make a concrete birdbath stem then put a big plant saucer or shallow bowl on top of it.
Below is a link to my blog post about it. I may mosaic it someday.
Cheap pots? Yard sales.
Kathy

Here is a link that might be useful: Birdbath mold

if u look around your shed or yard u can find all kinds of objects to use for making B-baths i have some pics in my webshots albums of different objects i have used.
Silvamae u have some great mosaics. the plastic B bath from the $ store works well
bonnie

Here is a link that might be useful: webshots

freecycle.org is a great resource for finding items to mosaic and even for tesserae. You can post a "WANTED" and also keep a look our for "OFFER" I got a bird bath from freecycle and also found a bottom at a yard sale for $1....it should be easy to find something for a top. Good luck!

My mother gave me a plant stand. One of those painted iron ones that you put a single pot on top. My plan is to buy a terra cotta saucer as the top, mosaic it and use the plant stand as the base. You can find those at yard sales and thrift stores really cheap.

Keep an eye open for large shallow bowls at thrift stores or garage sales. Put the base together from large old vases or a combination of flower pots and vases. Use thinset as the adhesive to hold everything together. I have found beautiful large bowls at garage sales for a dollar. The link shows a glass totem I glued together but I could have put a bowl on top for a birdbath ...

Here is a link that might be useful: Pieces of a glass totem