Get a job in the weed business so you have some money to spend.
Go to Costco and pick up some of the Kirkland stuff. I hear some of it is very good for the price. There’s a Costco wine blog that reviews wines regularly.
So, what are some big cabs from California to check out? Below $50…and I don’t have a friend with a helicopter…
Lol! Budgets really do increase that quickly once you get into wine. My #1 in this range is Venge Silencieux.
I’d check out Australia, Spain, Chile, Argentina, and even Bordeaux before I started looking at California.
For the style your looking for I’d look to Argentinian Malbec or Garnacha from Spain. Lots of drinkable stuff to explore in the $8-15 range in those regions.
Do you have a Grocery Outlet?
Your budget would go much further if you got out of California. You can find a few things in Italy and France, but Chile and Argentina are your best bets.
And many places offer a 10% mixed case discount. So if you can work that it might help a bit.
Find some new friends that have nice cellars/collections.
How did the budget go from $100 a month to $50 a bottle??
At this rate, very Soon you will be drinking petrus! 
I’d check out Smith Madrone. Very well balanced, well made Spring Mountain estate cab that ages well. Their riesling isn’t too shabby either and also ages very well.
Forgot to mention one of my favorite QPR bottles from Cali is Halcon Alturas. It’s Syrah from the Yorkville Highlands not too far north of Napa Valley. Absolutely killer juice and so affordable. Well worth seeking out.
I´ve no idea about US-market but there should be a lot from Southern France:
Minervois, Corbieres, Faugeres, Fitou, Roussillion, Cotes-du-Rhone, Costieres de Nimes etc. -
and always look at the label if they are bottled at the property (better no negociant bottlings).
Good (red) wines from these regions can be found in France for 4-9 € …
For white: Picpoul de Pinet … or Muscadet de Sevre et Maine
I don’t know or agree with all of the following, but it fits your theme
Here is another Bordeaux option at $15 and rated 90-92 by Neal Martin:
https://www.b-21.com/2016-Chateau-Cap-de-Faugeres/productinfo/FRCFME16AE/#.W-VSN7Q8KhA
A modern right bank Bordeaux, which is predominantly merlot, should appeal to a Napa Cab drinker. This wine should be easy to find. Incidentally, I recall paying $20 when the 2005 vintage came out.
And some more around $12-13:
https://www.b-21.com/2015-Chateau-de-Parenchere/productinfo/FRPAME15CE/#.W-VS7bQ8KhA
https://www.b-21.com/2015-Chateau-Le-Pey/productinfo/FRLPCS15BE/#.W-VTD7Q8KhA
And even a Sonoma Cab
https://www.b-21.com/2015-Louis-M-Martini-Cabernet-Sauvignon/productinfo/USLMCS15AE/#.W-VTyLQ8KhA
That is a great call.
As others have said, that is a really difficult price point for quality reds.
M. Chapoutier Domaine De Bila-haut
The Kirkland Napa Red Blend is drinkable, but not one of their best.
Explore other wines from Domaine Lafage
+1
That really helped me out a lot.
Reminds me of the time I “treated” my wife to business class on one of her overseas flights. She will never look at coach the same way, and this has become the source of some (heated?) conversation as we plan flights. . .
Back to your request. I think you have a lot of decent comfort in coach, I mean a lot of choice of wine in the $10-$12 +/-. Some of it very enjoyable, a lot of it “meh”. There a big world of wine out there, so it helps to get advice and you will get some on this forum. Ignore the comments that seem discouraging and sift through for suggestions. Since you prefer Cab, I suggest you give “Substance CS” a test drive. Might be slightly above your average price range but it is very good. If you are open minded, and are near a Costco, I would also suggest trying Kirkland Cotes du Rhone Villages (red) and Kirkland Ti Point Sauvignon Blanc (white). These are both about $7, and will give you room to “splurge” on occasion (well maybe not on first class !) ![[cheers.gif]](/uploads/db3686/original/2X/0/0ff9bfcdb0964982cd3240b6159868fbdf215b1a.gif "cheers"){kind=small}
-Jim
P.S. Welcome!