Hi
@Antitor, welcome to the forum!
The Mob7 is a great little quad, I have one myself, and luckily it has not blown an ESC yet! ?
1s batteries tend to be a little less sturdy than their multi-cell brothers, both because they are usually very small MAH ratings, and also because they are by themselves and don't have another cell to lean on. They are inexpensive, and it happens, but try to keep them at 3.85 volts in a cool dry environment when not being flown, and many will last a long time. I have some that are 3 years old and doing fine.
The radio is great, and the goggles are some of the best in their price range, so there is nothing wrong with those. Many of the best pilots, who aren't famous and rich, are tearing up the sky with that same equipment. And it is actually true that expensive top of the line gear can't make you a better pilot, and a good pilot can always adapt and fly with just about any junk they are handed. So while your goggles can improve one day, it won't be what makes you a better pilot, just a poorer pilot. ?
What Frsky Taranis did you get, a QX7, or 7S, or a X9D+ of some kind?
You can put together a great quad for less than $200 easily if you stick to good quality, but fairly priced parts, and stay away from the hype. There is a thousand little things to consider, and even more choices to navigate, to try and answer your question about "what to build", so here is a couple of things to think about before you go out and bye bye bye. Also, just so you know... almost everything can be made to work together within reason.
What prop size? 3", 4", 5", 6" 7" ??? 5" is the original sweet spot.
Individual ESC's or a 4in1??? While 4in1's are nice and compact and clean looking, when an ESC inevitably blows, and it will likely be sooner than later, you need to buy and solder a new 4in1 and that is expensive and a pain not to mention throwing 3 good ESC's in the garbage. With individuals, it is much less soldering, and much less expensive to replace.
A great beginner part list that cannot be beaten for the price is...
TBS Source One frame
Emax ECO or low end iFlight Xing for motors
Low end Diatone Mamba or iFlight Xing for a 4in1/FC stack or a CLRacing F4S and Spedix ES30HV for AIO FC and individual ESC's
Cameras... there are too many great ones to list, there are plenty of good choices made by Caddx, RunCam, and Foxeer.
vTX... again, too many to name, but I would look at Rush Tank series, PandaRC, RDQ Mach3, or maybe even splurge on a TBS Unify if I could find it on sale.
RX I would get an R-XSR, or maybe a XM+ depending on remaining budget.
Batteries... hard to go wrong with CNHL MiniStar series or Black series, but Tattu FunFly and RDQ make great affordable packs also.
Of course there are a ton of small nickel and dime things you possibly will need to build like various heat shrinks, double sided sticky tape, zip ties etc.
You will also likely need a good charger and a parallel charging board unless you want to spend all day babysitting charging lipos.
I can refine these things with what is available (and/or on sale) if you want, so just let us know.
Again, welcome!