I can't be sure, but that looks to me like a pretty nice bike. I have an '87 Brava, also a "mid-range" road bike, and I really like it. Like Narhay said, the trick to making yours into a superb rider is to fix or upgrade what is important.

For gears, that RD looks like a Suntour arx-GT which Velobase.com says can handle a 34T rear cog and accommodate 32 teeth of chain take-up. That means you could swap the FW for a 34T or 32T and climb just about anything. You'd need more chain links but you could use a new chain anyway. Try a KMC Z8, or SRAM PC-870 (for more money). New tires and cables, maybe KoolStop brake pads. True up the wheels, repack the hubs and the BB, and maybe the headset too. What size wheels are they, and how are your roads? I'd suggest you try 25mm Panaracer Pasela tires, maybe with their Puncture Technology (or whatever they call it now). If the wheels' measure about 19mm wide on the outside, 13mm in the inside, then consider 23mm tires if your roads are decent and you aren't too heavy. Some people argue that wider wheels roll more easily, but they are also heavier which you can really feel, which is why I like lighter tires. Then ride it like you stole it.

As for spending money, tires, chain, cables aren't free. But expense is a matter of perspective. A decent frame with good wheels and components will ride better than a great frame with lesser wheels. So I don't consider it a matter of what the bike is worth. It's a matter of what any upgrade is worth.