78 RPM RECORDS
Victor Phonographs will play any laterally-cut 78 RPM record. This would include most flat records, with the exception of the early Edison and Pathe discs, which used a vertical cutting method. Don't play thick Edison discs on your Victor, as these are vertically cut, and the Victrola's needle will ruin them. Victor, Columbia, Regal, Paramount, Banner, Aeolian, and a host of other brands will all play correctly. Some brands (not Victor) offered tonearms that would play either the lateral or vertical discs by rotating the soundbox assembly.
The reader is warned that playing 78's made after 1935 on a Victrola will cause the record to wear very quickly, as these records were designed for the lighter tonearms that were used on later electric phonographs. Thus, it is not wise to play "big band" or Frank Sinatra 78's on any pre-1929 acoustic phonograph. 78 RPM records were produced up until 1958, so many that you come across are too new for your Victor phonograph.
I'm not a record collector, and I have no information on the value of records other than to say that 99.9% of 78RPM Victor (and other brand) records are worth no more than $1 each in good condition, and many are worth less than that. That hurts a lot of people's feelings, but it's absolutely true. They made hundreds of millions of records in the Victrola era, and boxcar loads of them are still around, so the prices are quite low. I have no idea of where you can buy or sell records...I get all mine at flea markets and swap meets. I like buying them by the box (usually for $5 or less), and sifting through them later. I've yet to come across a "rare" one that was worth more than a few bucks.
Reminder: Steel needles were designed to be used ONLY ONCE, and should be removed and discarded after every play. Using a worn needle will cause rapid record wear. New needles can be bought from the sources listed on the RESOURCES page.
I recently was at a phonograph swap meet when a older gentleman drove up in a Ford F-150 full of old 78 records in wood crates. He started asking $10 for each record, and by lunch time, his price was down to $5 per crate. When I left the show, he was selling them for $2 per crate...and still had a hard time finding takers. He was heartbroken, as he thought he really had something. Those records just don't have a lot of value.