Order your test kit today. I swear by the TF-100 and the Aqua Check (salt) test strips - it is worth EVERY PENNY. I have a SWG and for our lifestyle (work, ball games 2-3 nights a week, etc) it is the only way to go as I don't have the time to test and add bleach every night. We start the season by filling the pool (from the winter lowered) test, vacuum, add the appropriate amount of salt (use the cheapest from WalMart SALT is SALT - pool or water softener as long as it is 100% salt you are good), get CYA level good, and add bleach during startup. During that opening time I'm adding bleach as the SWG keeps you level but you shouldn't use it to bring up your chlorine level when bleach can do it super quick and easy.
Once you are balanced then kick on the generator and you are done! Oh I don't add much of anything else the rest of the summer. I test to be sure and do spend time having to keep the PH down as it goes up but cost wise you aren't looking at much pool chemical wise....pool toys are another matter as I'm a sucker for another cool float.
This summer's opening cost
4 bottles 12% bleach - $7.99 (caught a sale)
4 bags of salt - $20
Stabilizer/CYA - $15
Done!