Yeah, pre DOS 3.2 max limit was 40Mb. I think DOS 5.0 raised that to 300-400Mb or somewhere in that range.
Drives that size do pop up fairly often on fleabay for (usually) not a whole lot of $$$. Or, if they have garage/estate/boot sales wherever you're at, you can usually find older computers you can salvage the hard drive and toss the rest or part it out. These are usually pretty cheap also.