After keeping four of these old bikes, I have the following observations that might help you:
1. Finding a clean, unmolested bike with complete documents is like finding a unicorn! If you find one expect to pay top $$$$ for it, sold a very thoroughly restored, legally imported, Khi registered 1997 model bandit 250 in 7.5 lac in dec 2023!
2. The biggest issue is finding a bike that is legally imported and has a complete documents file or one that has been actually auctioned by customs etc. Usually what people do is find a dying old bike with relevant lower value and punch the chassis number on a better looking ncp! an example is you will find a lot of bandits 250 with police, navy, army auction file. (GN 250 papers on GJ74 bandit etc)
3. The part are very scarce, and very limited people understand this bike! and those who do ask extra ordinary money (i rebuilt a good bandit 250 engine from a person I know and it costed near 2lac, the engine is still running strong after 2 years and 20k km).
4. The carburetors of these bikes though may look easy but are difficult to work on and will make you visit a mechanic every now and then!
It may look tempting but you will end up not enjoying the experience at all! you will have to learn a lot about these bikes and work on them yourself to keep them road worthy. Have faith in Allah and keep saving money! a good old trouble free EFI bikes in todays economy starts from 1.6~1.7mil!