They saw you coming at those prices...
The only thing you did not over-pay for by much is the panels, which you paid $1 per watt. 70 cents per watt is about the going rate on ebay.
Yes, you can buy the most expensive brand name components and be happy, but then you forfeit the right to complain about price. There are cheaper alternatives out there that do the same thing, argue quality comparison, but falls on deaf ears a lot of the time unless that is the specific topic of discussion.
I have 600 watts and 400 amp hrs.
panels $450 total
mounting hardware $0 (use scrap aluminum)
3M tape $15
Wires and connectors $50
Circuit breakers for DC $48
3x controllers $102 ($21, 21 then 60 for exact same item months apart)
400 a/h batteries $1300
DC-DC $100
Shunts $30
DC panel $7
Battery disconnect $17
Inverter $47
MT50 and dongle $30
3x Gland entry point $22
$2,218.
I might have missed some incidentals, but this is the bulk of what makes the system go. We are way apart on price, but you do have the name brand stuff. If we add another $450 to bring my solar up to your 1200 watts (SAME WATTS/SAME AMP HRS) then still Im under $3k. You have some luxury items on the list that is not needed to make a system run, but are nice to have. I also have a few small items that are not needed, but make life easier.
The answer is ease. Cranking a generator and putting gas in it is not what I want to be doing. Battery power is so much easier than generator power, battery power is always there and can be used as needed, one second at a time or all night long, or 24/7 since we have solar. You can have battery power with a gas generator just the same, run generator once per day to recharge the batteries ( a big chunk of your budget given the has-been name brand batts you have).
Yes, for me, it is worth the extra price.