For inexpensive computer parts post a free ad in Craigslist or search your local ads. I see people posting want ads for used computers all the time. I imagine they are using them for parts, perhaps you can give them a call or email and see if they would be willing to provide or sell you a piece they aren't using. They might even be able to connect the parts to your computer.
Hobbiests are always a good inexpensive contact. They enjoy what they do and seem to work for a fraction of the cost of retailers. I have met some wonderful people that have helped me with my computer, car, yard work and painting. I was quoted for a kitchen paint job by a professional for over five hundred dollars and a guy in my neighborhood came over and did a fabulous job for only $200.00 and even moved my items, cleaned my floors, installed a new oven fan and wiped my cabinets with wood cleaner! It was well worth it!
I had a computer person that I found in a want ad come and pick up several used computer items from me and then he stood to help me with my install =)