Yes the prices have shot up. I’ve never seen cpvc used like that or a fitting like that. The tank should have two 3/4” male nipples sticking out of the top. They make two types of flexible lines. I use stainless steel flex lines with female ends on both ends. On the hot side, just cut off the cpvc coming out of the wall and glue a 3/4” male adapter to iron pipe fitting. Install the flex line with two female iron pipe ends and your fixed. On the cold side, you need a cutoff. I don’t see one in the picture. I’d glue on another male adapter and install a 3/4” brass ball valve on the pipe coming out of the wall. Put in a 3/4 x 2” brass nipple in the out side of the ball valve. Now you can install the same flex line with two female ends on it as well. Don’t over tighten the lines. They have thick rubber washers inside. The fittings compress the rubber to seal. It does not seal on the threads. Cpvc uses special glue. Let it set up for a couple of hours before you apply pressure to the system. Hope this helps.