As an illustrative aside, this week I got the singularly dustiest and dirtiest 1951 Remington Super-Riter on the planet for $11 at a thrift shop, but it's still in fantastic functional shape and actually has the smoothest carriage I've ever experienced. A day's worth of work including a trip to visit the compressed air gun at the local car wash (for dusting), some exterior scrubbing, and dousing some of the internals with mineral spirits and brushing it out with a toothbrush, a few drops of oil on the rails, and it'll be a $400-500 machine. Total budget was $41 including about $20 of materials, $10 of fresh ribbon, and the rest is basic elbow grease.