Are you actually talking about a HOT TUB or a large tub with jets and whatnot like what would be in a high-end bathroom (or at least well-remodeled bathroom)?
If you're talking about an actual HOT TUB, unless you have a cathedral ceiling in your basement (highly unlikely, if not downright stupid) you'd be a fool.
The cost of throwing a hot tub in your basement isn't what you have to figure. You'll have to add ventilation fans, just like in your bathroom, and the probability of STILL having excess humidity will more than likely damage the wall materials and add condensation/humidity to the floor joists of the room above. You're adding a complicated problem to something when it's clearly better-suited for outdoor use.
Keep your HOT TUB outside, and use your warm TUB inside.
And if anyone is buying a hot tub because of its "value" and actually doing comparisons on maintenance costs, they should have never bought one in the first place.
