I was quoted around 22k, which is on the high side, you can get whole home ro units starting around $2-3k mark, but storage tank + install puts you around 5k minimum, some higher efficiency units can’t also be had for around $10k.

I am willing to spend so much because of the high efficiency, live TDS monitoring and the $20 per month full maintenance plan.

Some of the higher end systems require a lot of fiddling and knowledge to run properly, and most plumbers where I live know next to nothing about whole home RO, so having the maintenance plan which covers, parts, labor and replacement filters is priceless in my book.