If you have someone to help push then perhaps think about a wheelchair. You can buy portable travel wheelchairs that weigh 15-20 pounds for $150-$200. If you feel like walking, then you can use the wheelchair as a walker and sit when you need to. I'm not sure I would try to self-propel sitting in a wheelchair, but it should be safer than trying to self-propel with a rollator.
Also, portable travel wheelchairs are great to enjoy zoos and museums, too.