Nick Roney looks at Princeton Record Exchange’s discount CD wall. There are more than 150,000 items at PREX. (Photo by Suzette J. Lucas.)

It’s a place where you can talk with staff about Led Zeppelin’s blues and folk influences or quietly slide a $1.99 Cher CD onto the counter for purchase.

Not many music establishments can claim this, but with more than 150,000 CDs, records and DVDs crammed into a 4,300-square-foot store on Princeton’s South Tulane Street, Princeton Record Exchange has been doing it for quite a while now.

PREX — as usuals call it — thrives on this generalization. Merchandise ranges from new and used vinyl records, DVDs and used CDs in most genres, and a 16-person staff — most of whom have been at the store for more than 10 years — has enough music expertise to indulge customers in conversation, should the patron so wish.

But there isn’t much of a sales pitch at Princeton Record Exchange, and store general manager Jon Lambert prefers it that way. He thinks the store sells itself. Judging how merchandise constantly arrives and leaves Princeton Record Exchange, perhaps Lambert’s correct. He said offerings in some of the store’s departments can change by 50 percent every three days.

In fact, only two things aren’t constantly changing at Princeton Record Exchange: the staff and the store’s reputation as a place to go for music whether you’re from Trenton or Tokyo.

PREX marked its 30th anniversary in Princeton earlier this year, a nice occasion for a store that truly began in 1975 as a nomadic venture. Owner Barry Weisfeld would travel around, buying and selling records at street corners and bookstores. He lived in his van.

Weisfeld opened permanent shop in Princeton in 1980, and moved to the store’s current location in 1985. PREX has continued its positive trajectory, as the past few years have been among the store’s most successful in terms of visitors and sales, Lambert said.

Much of its business depends on used merchandise. Lambert touts his store’s role as a landfill bypass. Instead of people throwing away unwanted music, they use PREX as a way to get a few bucks for something that would have been rubbish. More than 4 million items have been sold in PREX’s history.

The store’s website said PREX will pay between $1 and $4 for most CDs, but Lambert cautioned that customers should not overvalue the merchandise they trade in. It is entirely feasible to hand over 13 CDs and receive $8 in return. At the same time, PREX management has paid top dollar for rare and in-demand CDs or vinyl records. The amount received for trade-in merchandise depends on demand for an item, as well as its condition.

Often, trade-in merchandise lands on PREX’s discount CD wall, which is very much what it sounds like. Lambert places any CD priced less than $5 on a very full wall that runs the length of the store. About 70 percent of all PREX merchandise starts as a budget item.

Lambert can count on a certain amount of sales, but he spends much of his time reacting to the unpredictable flow of merchandise into the store. One week may see a few thousand inbound items followed by a week of 30,000 arrivals.

“We can’t control our inventory at all,” Lambert said. “It comes when it comes, and we never walk away from a good collection. We never want to be in the position where we have too much merchandise and can’t buy. It’s opportunity. That’s our bread and butter. That’s why we succeed, because of the used merchandise. And turning that away is just an anathema to me.”

Yet having a lot of business seems to be a good problem to have, especially when a store belongs to a dying breed. The ever shifting landscape of the music industry has made many record stores obsolete, and Lambert said the store has focused on remaining current while staying true to PREX’s vinyl-out-of-a-van roots.

PREX has reacted to changing consumer preferences, like pricing more merchandise as budget items and carrying more new vinyl. More and more current artists are releasing their albums on vinyl, and PREX has gone with the trend. The store has 2,000 more pieces of vinyl in stock now than a year ago. Vinyl sales have jumped close to 200 percent in three years, Lambert said.

CDs still earn the most money, with about 55 percent of PREX’s sales in CDs to about 28 percent vinyl and 17 percent DVD. But Lambert has watched the trend closely because PREX matches up much more favorably with online retailers pricewise in vinyl than in CDs.

Lambert also has established PREX YouTube, Twitter and Facebook accounts, as well as a company website and affiliated music blog.

All shopping will remain offline, though, and he seems unconcerned about the movement toward digital music. Lambert said he loves the new trend of including digital download codes with vinyl records because it mixes the tactile experience of record stores and record packaging with new technology.

“As long as we’re reactive in a positive way, as long as we don’t stick to old paradigms, as long as we’re watching the trends, I feel like there’s a place for us forever,” Lambert said. “I see people having fun here every day. I see the smiles on their faces. I know people enjoy being here. I don’t see any real reason why that should ever stop.”

And all signs point to PREX surviving. Rolling Stone magazine recently ranked PREX one of the top 25 record stores in the United States, and the store continues to draw traders from as far as Japan looking for a good deal on a collection. An in-store survey revealed about 33 percent of PREX customers on a given day came to Princeton just to visit the store.

“This is a fun place,” Lambert said. “This isn’t a snooty place that’s going to judge you. No one’s going to sneer at you. No one’s going to make fun of what you buy. It’s not just for heavy metal bangers. It’s not just for highbrow classical. If you like music and movies, you will find something you like here.”