Teetering On A Precipice

I'm standing on the edge of a cliff here, and I'm really trying hard to not fall off, but it's really scary. I run a business and I run it off a very old (Win 98) computer system with a small internal 2-computer network containing my inventory, my cash register, and all of the other assorted things necessary to operate a business in this day and age. The inventory/cash register system program is proprietary. Several years ago I contacted the firm about an upgrade and they quoted me $12,000. Yeah - that SO wasn't going to be happening.

There is no way we could have afforded to
upgrade, and we still would have had to
re-enter every item by hand - more than
25,000 individual and linked items - before
it would have been operational. 

So I've been limping along. But now I'm getting some serious hard drive errors on my main computer and if that goes, I'm dead in the water. SO NOT GOOD! I sent an emergency "Help Me" email off to my computer guru last night and I hope he has some answers for me or a source where I could get a hard drive appropriate for a Win 98 desktop system, but who knows?

Finding parts for old computers isn't easy. I had to do
this a long time ago for another ancient computer that
bit the dust and that one never truly got sorted out.
I'm running out of options here and hope that I can
make this one work either with a new hard drive
or some serious computer work by Dale. 

Anyone in my readership who has a line on such a thing? I have to get this taken care of - installed, duped over, and basically salvaged - before my computer hard drive bites it. I'm absolutely terrified. Without an operational computer system, I don't have the ability to make sales, discounts, check customer records, add new items and remove old ones. If you have an idea about where I could locate a good functional hard drive for such an old computer, or if you have an old one sitting around unused that might work for me, message me please.

Got any ideas for me? Got an old computer sitting
around unloved and unused in the corner of your
basement that you might be willing to tear apart
and sell me the hard drive? Message me and let me know. 

Aside from that, well ... right now there really isn't any aside from that. This has to happen - no computer crashes allowed! Have a great Tuesday!