Sounds like your bike could really use a full-service at this point. Without seeing the bike or its full history, I'd guess its due for a valve clearance inspection, new plugs, air filter, full lube, fluid top-off, carb clean and sync, safety inspection and make adjustments to proper settings of chain, tire pressures, etc. You're probably looking at about $525 in labor to do everything described. Hare Racing's hourly rate is $75.
Service Forks and Shock: $120 Rebuild Forks and Shock: $180 Revalve Forks and Shock: $320 + parts = ~$450 Remove & Reinstall: $125