How do your tenants feel about the basement? If they don't like it, you can probably get them to help bust out the old floor for cheap. That may allow you to do a new floor and stay within the budget. Otherwise, I say either skim coat it enough to cover the craters, or just leave it alone.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.