Is it in good condition now? If it was well taken care, maintained by the book and driven responsibly... it will last as long as you need it to. I'd have to see/drive/inspect the car for myself to answer that question as accurately as possible. In general, the 5th gen 4-cyl. Honda Accords are very capable of 300,000+ miles. As was mentioned above, the AT's life expectancy would be more iffy. I've got 163,000 miles on my 96 and the AT still works flawlessly. I change my ATF every 30,000 miles w/ ONLY Honda ATF. Most of my mileage is on the highway, and I drive very conservatively.
As for dumping money into an old car, If you love the car and it isn't too far gone.. I say go for it. In the long run, it's cheaper than buying a new car.
I just dumped $$$ into my 96 refurbishing and upgrading it. This has included new paint (white gold pearl) new tires, new bumpers, new lights, new carpeting, seats (white leather) leather steering wheel, Acura CL leather shift boot, wood trim, new OEM rear spoiler, new OEM chrome rims, gold package, chrome door handles (from Acura TL) Acura CL guage cluster, Acura TL BOSE CD/cassette combo stereo, new Sony XPLOD speakers, new trunk lining, and heck... I even threw in some new wiper arms because the originals were faded!
This doesn't include the work I put into the mechanicals..
New timing belt/b-shaft belt/water pump/all seals/gaskets including new oil pan gasket.
New muffler and B-pipe
Recent major tune-up
All fluids changed
New accesory belts
New radiator
All new hoses, brakes, etc.. etc...
With the engine work included, I dont even want to calculate how much I've spent total.. but I'm sure its worth more than the car!
But in my situation, I plan on keeping my car for a very long time. I've had it since it was practically new so I know it's been extremely well taken of and was a good car to start with. In any case, if something happens to the engine later down the road, I'll just swap in an H22.
Right now, it looks and runs like a million bucks... so I should be set for a long time...