Thanks for the advice Chris. Back in August when I was thinking of starting over - it was leaning more towards an upgrade - which would break the bank (I get that). The only things transfering over would be the fish. Everything else would be new. (Even easier)
The only thing that concerns me with your method - I'm assuming you'd leave the rock in the tank to be treated with muriatic, yes? (Yes, this is safe, effective, and takes the least time and money). I'd be concerned about the rock (all Pukani) retaining the tap water. I'd also be concerned because the muriatic would react with the rock like a calcium reactor would - so the muriatic would be consumed and converted to Calcium Chloride - which wouldn't really help to leave it running. (No need to be concerned. The Muriatic acid will be effective. Whatever minor amount of conversion to calcium chloride will be inconsequential. You aren't adding enough acid and its just enough to sanitize the tank. Any residue will only have a side effect of temporarily pulling down your alk a bit. Once drained and refilled, you will be back to an alk of 8.0 in a day or two with the help of a little baking soda.)
I'm still leaning on a reset with a new 300. Just waiting on FAOIS to come back with their quote. Got my quote from Felix @ Reef Saavy. (Costly to upgrade and more importantly to maintain in salt water changes alone. I wouldn't try this now. Wait until you have had at least a year of success with your current tank.
The other way I'm leaning is just throwing in the towel and selling everything off. I'm tired of looking at all the aiptasia in the tank. I'm tired of being tied to the tank (I really need a fish sitter so I can take a vacation!). You spend a lot of time on RC so you have a passion for the hobby. If you want to make it ultra low maintenance, do the reset this way and your aptasia will be 100% eradicated in a week. Then make a deal with yourself that you will keep things easy with a FOWLR only setup for the next 12 months or so. I personally like fish better than coral anyways and have considered doing the same if I hit a brick wall down the road. Fish for me are by far the cheapest and easiest to maintain compared to the corals. If you don't have them already, get an auto fish feeder and a reliable ATO. Then you can take vacations and trips and you only need an occasional check in from a friend or neighbor. A small 10w pump running on a cheap UPS 24/7 is also great insurance from the occasional power outage. I crashed my previous tank 3 or 4 years ago, sold everthing and swore that I wasn't going to get back into the hobby until I retire. Low and behold, after 12 months out, I was itching to get back in and had to spend $6,000 to "do it right". If you get out, you are likely to find yourself lurking on RC like I was and you'll end up right back in after the retreat is over. Something to think about.