Bundy is a "student" horn produced by Selmer. I'm curious...why would you buy something and then
ask what it is?
ANSWER: Because they got a great deal on a quick sale.
Welcome to SOTW, Bigfun! This is (without exaggeration) the greatest concentration of saxophone knowledge on the planet. Use what you learn here wisely. With great power and knowledge comes great responsibility.
Your Bundy has an interesting linage much discussed here on the SOTW. The serial number is not from Selmer, but is a continuation of serial numbers from Buescher. From the early 1900's through the 1950's, Buescher was large maker of musical instrument and they made what I believe were the finest saxophones ever produced in the US. And they made many of the lower-end saxophone models sold under the Selmer USA name. Selmer USA usually labeled these HA Bundy after one of the heads guys at their company. In about 1961, the Buescher company fell on hard times and was bought out by Selmer USA. At that point, Selmer USA began making practically all their saxophones (mostly student and step up) at the old Buescher factory using the same Buescher equipment.
Your Selmer Bundy is from around 1978. If it has the left-hand bell keys, it is a student model Bundy "Model I". These were made using the pro-model Buescher Aristocrat design but with some simplifications used to reduce costs and help with mass production. To help confuse the issue, after the buyout, Selmer USA also offered a step-up version of your sax under the Buescher Aristocrat name. But it is virtually the exact same as your Bundy.
These can be very good and very durable saxophones. They are often bright but have some of the original pro-model Buescher tone from the 1940's and 50's. The keywork is simple but very durable. Some have intonation issues, but others play very well in tune. As with most student models, quality varies from horn to horn. There are good ones and bad ones. Some are very good and have even been used as main instruments by pros and even some jazz greats. I still see these used by street performers quit often. In good condition, it's worth about $250. Many can be bought on eBay in the $100 to $150 range but usually need adjustments.
Congratulations on your purchase. These can a be pretty good for a low-cost sax.