Hi, and welcome to AK.
I don't know about that (that you will or won't appear on PBS' Antiques Roadshow or that your radio is worth as much as you said), but I do know you now have a very nice Zenith radio, and yes, it is an antique. I have a slightly newer model here (K731, from the 1960s; yours is model M730 from the '50s), an ebay score last year. My set worked as soon as I received it here, and I still use it regularly. Works great, as do all Zeniths. I also have a 1951 Zenith H511Y "racetrack" model in a black bakelite cabinet that works rather well for its 53 years, but needs a bit of work (the speaker cone is torn, the set could use a recap although it still sounds good, and the dial cord is broken; it probably could use a new line cord as well).
I just scored a NOS (new old stock) 5" Zenith loudspeaker on ebay yesterday which should arrive here by UPS or perhaps USPS in a few days, so I'll be able to replace the speaker soon.
I like anything and everything manufactured by the original Zenith Radio Corporation of Chicago. Used to have a basement full of old Zenith TVs, radios and even one early-'60s vintage Zenith stereo phonograph when I lived in suburban Cleveland in the late '60s and '70s. However, I moved to a very small apartment four years ago, so must be content with collecting small radios (my small collection presently consists of the two sets I mentioned above). I still enjoy looking at and reading the posts by others here on AK about their TV scores (b&w and color--all my old sets were Zenith b&w portables and one 23" console); I also like reading about those of our members here who have the big 1950s Zenith 3-way console entertainment units, especially the Great Circle sets with the 19" round tube. I hear those were excellent sets when they were new and still are today, once they are gone over electronically (new tubes, caps, etc.) and the cabinets shined and cleaned as necessary.
Again, welcome to AK. Enjoy that "new" Zenith of yours; as I said, it is an excellent set (the cabinet looks great as well), and should serve you well for many years, as Zenith's early tube sets were built to work well and to last.
Kind regards,