New 45s in the 1960s sold, generally from $0.69 through $1.00. After a few months of little or no sales, they were placed in 50¢, 3 for a Dollar or 4 for a Dollar bins, along with DJ copies. After a while there, not selling, they went to 10 for a Dollar bins. Other sources were Woolworth's Walgreen's 10¢ sales, and thrift and junk stores, where they might go for anywhere from 5 to 25¢ each. There were the warehouse sellers, who might sell large stocks that couldn't be "cherry picked", but might have hundreds of valuable gems among a lot of worthless records, and the overall lots could average from 2-5¢ per 45.
Often, in thrift stores, I'd throw a large bunch of 45s (R&B and Soul) into a box and offer, say $5.00, and get them for an average of 5 to 7 cents. The Thrift store people were happy to get anything for them. They were surprised anyone would want them. I used to pay from 25¢ to 50¢ for LPs. I couldn't afford to pay even $1 for a big volume of LPs . I reserved paying that price only for records I wanted really badly, and knew might not be found for lower prices.