A few random thoughts for the OP:
--Your financial assessment is skewed. Few Tesla owners need a HPWC or dual chargers, and your 14-50 cost seems high, so you can't really claim all that as 'savings'. Also make sure you factor in TOU/EV rates, if applicable. With a little bit of lifestyle adjustment you can time shift a lot of your major power usage (W/D, dishwasher, HVAC, water heater, etc.) to the off-peak rates.
--You can certainly defer the cost of a 14-50 and just charge off 110v in the beginning, but as others have stated you will quickly find that the convenience of charging at home is invaluable. It really is the game-changing aspect of BEV vs ICE. There's definitely a benefit to 'local supercharging', but forcing yourself into making supercharging a necessity (as opposed to an opportunity) is going to get old, fast. Don't deny yourself the BEV owner experience.
--If you aren't already, you should seriously consider used/CPO cars. You can probably get into a 60 for under $50k on the private market. Your monthlies will be significantly lower, and you'll probably lose as much in depreciation over the rest of your ownership than you would lose in the first year of a new vehicle. The most important thing to remember is: Model S is just the beginning! Model 3 (for instance) will be at least as technologically advanced as a 2015 Model S, at a lower price point. You don't need to dump all of your eggs into a dream-car Model S. Buy a used car, drive it for 3-4 years, then upgrade to something better.
--There are some who are quick to shame over the 'ethics', but its not a big deal. Just use a little common courtesy. If all the stalls are full and someone pulls up, unplug and be on your way. They're probably a local too (other than holiday traffic, the only reason superchargers get clogged up is from locals), but...do unto others, and all...
--There are also some who claim local supercharging is simply wasted time (and they cite some equivalent hourly rate as supporting evidence), but that's a pretty unimaginative way to asses the opportunity of local supercharging...especially from folks on a forum that embraces alternative transportation. The key to making local supercharging efficient and useful is to think alternatively about how you spend your time; making local supercharging 'worth it' is all about time-shifting your other daily activities. The easy one is work related stuff--if you can slog through your emails or dial into a telecom or work on a presentation while at the supercharger, you're cooking with fire. The other easy one is The Internets--if you're going to spend time on your couch skimming through TMC at some point in the day/week anyway, a supercharger is a perfect place to multitask that activity. If your supercharger has nearby services (grocery store, etc) you can squeeze in some errands. Some people whip out a care care kit and go to town while charging. How often do you call Mom...and how hard is it to find time to do so during your otherwise busy day? Do you read a lot? How about keeping a book in the car? Do you (or, <ahem>, should you...) walk more? I've actually seen people pull out a lawn chair at the charger just to get some sun! Brilliant! The sky is the limit--you just need to apply the same progressive thinking to that 30 min of your day that everyone else applied to their decision to buy a Model S in the first place.