Most listings are in the $20's per square foot per year. The Salem submarket is going through a a rise in rates. In the last 3 months, the median rate increased $8 per sqft per year. That's a 50% increase in rent.
In the last 90 days, 91 listings have come on the market, so you'll want to check back regularly for new listings. About 35% of the listings in the Salem are subleases, so you might be able to sign a shorter term by taking over a previous lease. There aren't many listings below 2,000 square feet on the market, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,500 sqft. Most properties in this market are approximately 2 stories. Most buildings in this area were built in 1984 and are Class A.