To be exact on all these things I could not tell you since I do all my own work. My car is coming up on the coolant, T-stat and trans fluid change. If you search the site you will find others who paid a shop to have coolant and trans fluids changed. The air filter and cabin filter are easy, you will have to remove the glove box in order to access the cabin filter. If you can use a Philips screw driver, you can do this. The best place to buy them I have found is to order them from CG Enterprises. They are in Canada you can call them to order too. I have bought from them before and got an extra while doing so. $14.45 total. Here is the link I posted after I bought from them and asking if I could do so.
http://forums.genvibe.com/zerothread?id=11745Air filters are easy too, I have the AC Delco filter number at home if you need it. I get mine at Murrays Auto Stores. $8-$10.00My car is also due for a PCV, I checked mine and it is time. Again, if you can turn a wrench you can do this. It resides under the black engine cover, has a rubber hose going to it of course and is threaded into the engine. Top right rear corner, 20 mm wrench. I have no part number for it yet, there are two different ones according to my dlr. One for the GT and non GT, different thread pitches. I will be getting one soon... Plan on a few bucks for this part. The belt, unless you have done them before you may not want to tackle this on your own. I just saw a post recently of someone here that has done it. I have tools with the leverage needed and designed for removing belts, it makes it easy to do. Guessing $25-$30 for the belt only. $100 total for a garage to do it? I would get the Techron Fuel cleaner regardless... It is only a few bucks and even though you use higher octane, you still need to clean the injectors. I use it in my Vette and quoted from a Master Vette Technician friend of mine, the Chevron is the same as the GM and it will cure pinging under hard acceleration. Usually for the guys that "grandma their Vettes" around town. I do not have a pinging issue with mine since it is a manual and sees high RPMs! I drive it the way it was built for. Anyway, Vettes use premium as well but the injectors still need to be cleaned. If you have never used it, I would now and it is easy to use and buy. Murrays auto or WalMart carry it.