Real estate agents may be thinking these are both the best and worst of times to be in the market.

Eighty-nine percent of agents in a new survey said now was a good time sell a home, up from 83% in 2015, the highest percentage the four-year-old poll has recorded.

At the same time, only 34% thought the time was right to buy a home, way down from 45% last year and the lowest percentage since 2012.

Redfin, a real estate brokerage, polled 836 agents in 38 states and Washington, D.C., earlier this month.

Researchers asked agents why potential sellers were reluctant to list their homes. Forty-five percent said they worried about not finding a replacement home.

Sixteen percent said they were waiting for a price increase, and a mere 1% said they were afraid their home would not sell.

“Many of my prospective home-selling clients start the process by shopping for a replacement home first before they pull the trigger on listing their home,” Redfin real estate agent Sabrina Booth said in the report.

“Once they experience how competitive the market is for homebuyers, it gives them pause, and some choose not to sell.”

One in three agents surveyed said low inventory was the biggest challenge sellers currently faced, up from one in six agents surveyed just four months ago.

“Builders still aren’t providing enough new construction to satisfy demand, which means the market is desperately relying on homeowners to decide to sell,” Redfin’s chief economist, Nela Richardson, said.

Richardson noted, however, that new listings increased by 12% in February, a trend she said was continuing into March.

One bit of good news for buyers: In the first quarter, sellers were becoming more realistic about their home’s value.

Thirty-four percent of Redfin agents said unrealistic expectations about how much they could get for their home was their selling clients’ biggest challenge, a significant decline from 57% who said this in late 2015.

Given how tight the market is for all buyers, Redfin asked agents what recourse existed for those who could not pay all cash.

Waive contingencies or make other concessions, 47% said.

Twenty-six percent said being prequalified for a loan and having financials in order would improve the chances of having an offer accepted. Just 15% suggested being the first to make an offer.

— Check out The IRS’ Gifts to the Real Estate Owner on ThinkAdvisor.