I bought a 65 Midget 2 years ago which was a major find in my 35plus years of owning and restoring LBC's. It had 14,000 ORIGINAL miles! I have refurbished the fuel system, put on new rear springs and unfortunately replaced the wire wheels that had been dealt with very badly by some ham handed tire jockey. All new seals on engine and axle as well as tapered bearings in front. The car rides like it was new with almost 17 K on it now. My purchase price was $4,000 but I honestly have never seen an LBC so like new and unmolested.
I would say the Sprite is worth $3,000 but less any costs you figure to repair the "axle problem" and any other major shortcomings.