There are a blue billion of them out there. The best place to find them is an antique or vintage store. Yard sales are also good. You’ll have to get around a bit to build a nice collection, and it will probably take a while. You’ll probably pay a bit more in shops too, but keep reading and I’ll tell you why this is the best place to find them.
You will find a wide variety of radios online at sites like eBay, Etsy, and others. The problem with buying radios online is the shipping. Not only the cost, but moreso the lack of sense people use when packing a radio. Some models are extremely fragile. Bakelite and plastic models, especially early ones with a metal chassis, often only have a few screws holding the hold thing to the plastic material. If they are not packaged EXTREMLY well, they WILL break in shipping.
I’ve seen more than one YouTube video of someone pulling a mangled radio out of a box in pieces. I don’t have a lot of personal experience, but of the 3 radios I have purchased online, one of them arrived somewhat demolished.
You can find these radios at some pretty decent prices and many of them are in surprising condition for their age. You can also find restored versions, but expect a bit more for those. I have found that sites where you wouldn’t really expect to find vintage radios like Etsy will either have really great prices, severely inflated prices, or a mixture of the two.
If you want to shop online, but don’t mind a drive to pick up and pay for your find, Craigslist is a viable option. This negates the need for shipping, so no crumbled radios. You might find some great yard sale prices this way. Be careful. Always meet you seller in a populated area.
Where are some good places that you have found radios?