Homeowners spend an average of $21,000 prepping for a sale

• Americans selling their homes can spend nearly $21,000 making repairs and paying agent commissions.
• Sellers often overlook costs like painting or staging when they're preparing for prospective buyers. 
• About one-quarter of sellers who made improvements sold above the list price, versus 15 percent of those who didn't. 

Landscaping yards, cleaning carpets, redoing kitchens with fresh coats of paint — it takes a lot of elbow grease to get homes ready for market. After agent fees and closing costs, Americans nationwide can spend nearly $21,000 to prepare their homes to be sold, according to a recent Zillow report.

It's a hefty price, especially for first-time sellers who may not foresee all the hidden costs and expect more of a return on their investment. And more than half of owners now selling homes are doing so for the first time. But the extra effort can pay off: About one-quarter of sellers who made improvements sold above the list price, versus 15 percent of those who didn't.

"Sellers should remember that by taking care of these projects, they can get a really strong return on their investment and may be more likely to sell their home for the highest possible price," Lucas Puente, Thumbtack economist, said in a statement.

Home sellers should start researching costs a year in advance to properly allocate the budget and time to get their homes ready, especially as the housing market gets more competitive for sellers. Buyers can be more choosy as more inventory comes onto the market. "Selling a home was hard when it was a seller's market, and it's hard now," said Skylar Olsen, director of economic research at Zillow.

Costs vary by location

Closing costs alone, including agent fees or sales taxes, average over $14,200 nationwide. Because they depend on the home's sale price, they can easily change depending on where the seller lives. In San Jose, California, closing costs can add up to more than $76,000 before any home-improvement projects. In Cleveland, sellers can spend just about $9,000.

Before they even contact real estate agents, however, homeowners spend time and money just to get their homes ready to attract prospective buyers. That means painting interiors, replacing or repairing flooring, or remodeling the bathroom — all by paying contractors or taking the time to do it themselves.

It also means keeping the homes clean, scheduling child care for when the homes are being staged — and looking for a new home to move into. Said Olsen: "The hidden cost of selling your home is coordinating all of that and paying the bill out of your pocket."