SOMERVILLE — Consultants working on the embattled Green Line extension revealed on Wednesday that the original design of a nearly 2-mile community path alongside the project would cost about $100 million, an expense that officials are hoping to pare.

Officials at a community meeting at Somerville High School said they have designed a new path that would cost $20 million instead.

“We’re doing our best to deliver a project that we can afford, but that you can accept,’’ MBTA general manager Frank DePaola told the crowd.

The T in 2014 had estimated the path could cost about $40 million, but that number likely did not include the price of several necessary walls and other features — expenses that officials now want to cut. Until Wednesday, officials had not released to the public an estimate of all the costs of the path.

After officials revealed last year that the total cost of the long-awaited project could be $1 billion more than previously estimated, the new board overseeing the MBTA said it would choose to proceed with the extension only if costs dramatically dropped. State officials will decide on May 9 whether to go forward with the project, which has already won approval for nearly $1 billion in federal funds and was originally projected to cost about $2 billion.

Supporters at Wednesday’s meeting urged the state to build the project, including some version of the biking and walking path alongside it. Justin Maloney, who lives in Somerville’s Winter Hill neighborhood, said the community path would give residents a safe way to travel through the city.

“The path is at least as important to us as the Green Line,’’ Maloney testified.

As officials look to cut costs, extension advocates such as Ellin Reisner have worried that a community path — which she considers indispensable to the project — may get the ax.

“It provides much better access to stations,’’ said Reisner, who helped found the Somerville Transportation Equity Partnership in 2003 to make a concerted push for the project. “It doesn’t make any sense not to include it.’’

The fight to preserve the path is one of many frustrations for longtime supporters. After years of advocating for the project — and eventually seeing it win state and federal approval — those same supporters say they’ve been stunned to learn the project may be scrapped or be stripped down substantially.

“It’s like we’re starting all over again,’’ said Reisner.

But state officials — including Governor Charlie Baker — have said a more conservative budget is necessary if supporters want the project to be done at all. Already, consultants have said they could save about $200 million by stripping station designs to the essentials: Five of seven planned stations for the extension could transform from enclosed buildings to bare-bones, open-air stations similar to most Green Line stops.

The commitment to the community path came as a big victory to longtime supporters of the extension: In April 2014, Governor Deval Patrick’s administration announced with fanfare that it would pay for a path, projected to cost $39 million at the time. When T officials applied for federal funding in 2015, a budget line related to the path pegged some of the price at $27 million, but did not include other associated costs.

Jack Wright, the consultant who has been temporarily overseeing the Green Line extension as the T searches for new project leaders, said the original path was eventually so expensive partly because of the high retaining walls that had to be constructed alongside it.

Under the new design, the path would be farther away from the stations and tracks in some areas, so that the T could avoid building the walls. But that means some big changes. For instance, instead of running near the Green Line tracks in the section near Washington Street to around North Point, the path would run along the busy McGrath Highway.

Several supporters expressed concerns about that particular change, saying many cyclists and pedestrians would be reluctant to travel a path along McGrath Highway. Others worried that the new path had fewer entrances from the street and could take away access from communities that need it most.

Officials said the path’s design was ongoing and they would consider other ideas. A group called Friends of the Community Path has submitted their plan with a cost of about $19.4 million. DePaola said the T would consider it.

Wright said he knew that the new path design may not include everything that supporters had sought. But it was necessary to cut the costs, he said. “The goal of the interim project managing team is to get the [extension] back to being built, to bring Green Line service back to Somerville,’’ Wright said. “Everything else besides that service, is somewhat secondary.’’

Nicole Dungca can be reached at nicole.dungca@globe.com.