[34saving]

I guess I don't know if there is a used trailer market in your area, but if there is, have you checked it out? (I suspect a '90s trailer would be a big improvement over a '60s one.) It would be great to make somebody else take the depreciation hit.

Also, do you like the land/area you're in? There are manufactued homes available (at least here in MN) that are built in factories, but assembled on site. Often these houses are put on full basements, which would allow you to double your space without taking up more yard. I don't know if your area would allow that, but it's something you might want to look into.