In 1987, I think you'd be very lucky to have that much RAM. 4MB and higher only started becoming standard as people ran Windows more - so Win 3.1 and beyond, and that was only released in 1992.
4 MB was considered a large amount of memory until the release of Windows 95. There were people who had that much, but it tended to be the domain of the workplace or people who ran higher end applications.
If I recall correctly, home computers tended to ship with between 4 MB and 8 MB of RAM just before the release of Windows 95. There were also plenty of people scrambling to upgrade their old PCs to meet the requirements of the new operating system, which was a minimum of 4 MB RAM.
It was over $100/MB for RAM in 1987. The price was declining until about 1990, then froze at about $40/MB for many years do to cartel-like behavior, then plummeted when competition increased around 1995. I was there when the price of RAM dropped 90% in a single year.
If I recall correctly, home computers tended to ship with between 4 MB and 8 MB of RAM just before the release of Windows 95. There were also plenty of people scrambling to upgrade their old PCs to meet the requirements of the new operating system, which was a minimum of 4 MB RAM.