"Thoughts on Cost", that is the title of the thread.
For what you have it is pretty good.
But .. taking the other position; $540 (+$150) for the other additions (= $700), makes the beer you are going to produce expensive.
I know it is a hobby, and a number of folks say cost is not important and compare it to golf or the like. Most of them are the people with expensive rigs wanting to rationalize having spent a lot of money on gear.
A number of people like me view the hobby as a challenge to produce beer, both, better and cheaper than you would pay in the shop.
You can buy a lot of beer for $700. You brew 700 beers (~14 x 5 gallon batches), and it adds $1 to every bottle. You brew 7,000 beer (140 x 5 gallon batches, or about 4 years of legal maximum brewing) it adds 10 cents to every beer. This is a long-term commitment.
If it takes your beers to the next level and you stay committed to brewing for many years, it is worth it.