I'm really posting this just to brag and reinforce how good the theories here are. I started out a month ago with 0 chlorine, ta at 330, 0 cya and ph at 8+ (and serious calcium deposits on tile). Pure neglect on my part. Pool store told me to shock stabilizer and add acid (ends up being good advice). Immediately I started seeing results when I tested with my 4 way kit I bought at HD for $14. A few days after visiting the pool store I found this site and I decided to employ the BBB method and techniques for lower ph and ta which were not and have never been mentioned at the pool store.
Well, it took a month but I finally have my number where I feel good. cl is 3, ph is 7.2, ta is 70-80 and cya is 60. I'm sure the ph will creep up so I'm not worried about it at this time. My pool has never looked better.
So for my question. I feel like I got incredible results using a low budget 4 way test kit. So, is it really worth the $70 to go for a more advanced kit? It seems to me the theory here is so simple a simple test kit will suffice.