1995 Corolla

For this generation of car, there are two ways to approach maintenance: wait until something breaks, or preemptively catch problems through preventative maintenance. If you want the car to run as long as possible, the second option is preferred.

Your oil change interval would be driven by how you drive the car and what oil you use. For some - changing the oil every 3K-5K miles is fine. Others can run it 10K-15K miles or more between changes. Given the mileage of your car, I would not go beyond 5000 miles/6 months between oil changes. Everything printed in the Toyota factory service manual is the "minimum" you need to do to keep the car running. They have two service conditions (normal) and (severe). I'd recommend that you stick with the "severe" service conditions, as "normal" operating conditions is subject to wide interpretation. As just about everyone out there has driven in conditions that would fall under the "severe" operating conditions - you admitting that you could have done more to the car, maintenance wise, automatically drops you into the special operating conditions.

Since the maintenance history is unknown - assuming that nothing was done to the car, aside from items mentioned above (struts, alt, etc.). They recommend timing belt, timing belt tensioner, and waterpump every 60K miles. I know that you could stretch it out a bit more, but pushing it out to 90K - 100K miles is borderline playing with fire. This will probably be the single most expensive maintenance item to do on this engine, much of the maintenance can be combined at this point, as much of the parts will be coming off anyway to get at the timing belt. This included the waterpump and v-belts for the accessories.

Replacing the cap and rotor, plugs and plug wires are the norm for this car generation - if running platinum plugs, replace every 30K-60K miles or as needed. Cap, rotor, plug wires - replace at 90K-120K miles would be a good thing - at this mileage, they should be showing some wear. Drain and refill all fluids - brake (DOT 3 or better), power steering, coolant (Toyota Red - 100% coolant + distilled water). If you have a 5-speed standard transaxle, replace that gearbox oil atleast every 30K-60K miles, 3-speed and 4-speed automatics, drain and replace every 30K miles, pan drop and filter cleaning/replacement every 60K miles. With the 3-speed, you have a separate differential that would need to be drained and refilled.

Probably couldn't hurt to clean out the throttle body, clean the injectors (use a good in tank cleaner to start - Redline, Chevron w/Techron, Gumout Regane, Valvoline Synpower, etc.)

Clean up the battery posts as well, if the battery is especially dirty, remove from the car and clean it (baking soda + little water), dry and replace. Replace the PCV valve every 30K miles, if the car is not running 100% smoothly, might want to hit the EGR and clean the carbon out of it, same goes for the IAC valve.

There are quite a bit of information on this forum - just do a search for maintenance and DIY tuneup - lots of the points I've touched briefly here are mentioned in greater detail.

With the manual transaxle - drain and refill is all you need. Brakes will need to be flushed, only way to get all the old fluid out - bonus is that you bleed the system in the process. Coolant should be flushed out with distilled water - no need to chemical descalers or similar. Don't forget the master clutch cylinder reservoir - also doesn't hurt to bleed that system out as well. Powersteering fluid - you can just siphon out the fluid in the reservoir and change it at short intervals - eventually, you'll dilute the existing fluid to the point where it is mostly "fresh" fluid.

It is financially worth it? That is up to you. This generation of Toyota is known for longevity, especially so with good maintenance. It is fairly forgiving, but there are many wear items that will eventually reach their max lifespans. You could try and do some of the work yourself and leave the more complicated tasks to a shop. You'll be surprised how easy it is to do many of the routine maintenance items on the car. You don't even need to own tools - as many autoparts retails will loan you the tools for free.

As for your estimate - timing belt, tensioner, water pump, v-belts, cap and rotor, plugs, plug wires, injector cleaning, all fluid replacement (drain and/or flush) - $1000-$1500 is pretty much in the ballpark. Which is also about how much the car is worth as well, but keep in mind it is much less than what it would cost to get a similar replacement vehicle.

I'd prioritize it on the critical parts that would be hard to change yourself: Example

Timing belt, tensioner, waterpump, v-belts you could have done for around $400 or so at a dealership - some independent shops can get them done considerably cheaper.

Coolant flush will run about $70-$90 at a shop, cost you about $6 in distilled water and $26 for a jug of Toyota Red Coolant (100% coolant, not premixed) if you do it yourself.

Note: if you replace the waterpump, flush the coolant. If you pass on the waterpump, keep in mind that it would cost you about $200+ in labor alone to tear the engine back down to get at the water pump, if you did it with the timing belt replacement, labor is basically limited to removing the pump and replacing it.

The rest of the maintenance items, you can do yourself - you can pickup a Haynes Service Repair Guide to give you an idea of what it takes to do that task.