Need info regarding transmission fix

Have seen a lot of threads here, but not to the point that I feel satisfied with the answers, so if you posted a reply before, please reply to my thread as well. Here is the jist of things. 97 trans sport. No shift 1-2, so starts out obviously in 2nd gear. When it gets to 4th, not much change in RPM's from 3rd, running about 3,000 RPM at 65mph 3,200 at 70mph. Had it checked some time back at a dealership, told me 1-2 shift solenoid, which must be the same as TCC solenoid??? They said $1,400 to fix, which seems to be the routine number they give everyone that they don't know and assume know nothing about cars. Autozone has one online for $28.99 and says it does all the same functions, just located in different place??? And where in the heck is this solenoid located so that I have an idea how angry my mechanic will be (he's also my brother- 8yrs older than I) when I ask him to replace it before Christmas so I can enjoy my 5hr drive to the in-laws. Please a very good description and possibly an actual diagram of where this 1-2 shift solenoid is located would greatly be appreciated.

Indeed solenoid A need be applied for 1st as well as for 4th(OD) gear. http://www.autolib.diakom.ru/CAR/Pontiac/1997/Trans%20Sport/SYSTEM%20WIRING%20DIAGRAMS/
www.avigex.ca/xport/transmissionranges.jpg
www.avigex.ca/xport/transaxle.jpg

To access these solenoids anyway one must remove the left (driver) side cover ; the left drive shaft passes through and must be removed before. THere is not much room to access these ..but one member changed one on a 3T40 (3.1 engine..shaft aside) http://www.automotiveforums.com/vbulletin/showthread.php?t=551757 ; one tried to change one on a 3.8 with the shaft in place but did not report final outcome.

Welcome to AF.This should be scanned with a trans function scanner for codes, solenoid functions and slippage errors. A trans scanner can command and confirm all operations for a proper diagnosis, anything else is expensive guesswork. Forget AZ parts, use oe or quality parts from Napa. If it is the solenoid pack the side cover must come off, axle removed, subframe dropped for access, about 5 hours for an experienced tech working in a shop environment.