https://www.amazon.com/dp/B07BLJBYTM/ref=cm_sw_r_cp_awdb_imm_6QYFCMG7PZQNGA7EEEVE
I use this bag. I have 10 100card boulders in the bottom compartment. The top compartment can hold more if needed. The tripod spot can hold a playmat case. You can also slip a 60 card deck in front of several of the 100 card decks. Laptop spot for trade binder.
I'm a huge fan of Boulders personally. They are simple, look good, cheap and do their job well.
> I also use this camera bag to hold them - https://www.amazon.com/USA-Backpack-Compartment-Accessory-Compatible/dp/B07BLJBYTM/ref=sr_1_6?crid=29NXV9ABRW496&keywords=usa+gear+dslr+camera+backpack+case&qid=1656547910&sprefix=usa+gear+dslr+camera+backpack+case%2Caps%2C98&sr=8-6
It is currently holding 3 rows of 4 boulders in the large compartment, 2 boulders and a dice bag in the top compartment, a trade binder in the laptop slot, and my playmat in its case is in the tripod spot. Its nearly perfect, only thing I did was cut the waist clips off.
I use the linked bag and Boulder Cases. It currently is holding 14 Boulders, a small dice bag, trade binder, and the tripod spot holds my playmat in its tube. I could fit 15 Boulder in it if I had to....
As far as your decks go, I figure there comes a point where precons arent really worth getting anymore unless your are just dead set on grabbing every newly released precon no matter what. I would suggest using that money on upgrading a few of your favorite decks instead.
I bring most my decks just because I like to be able to sit down at any table. Sometimes I get to use my strongest decks, sometimes I need something a little nicer to use with the new guys at the LGS. Being able to scale up or down on the power level is nice. They are also all stored in the bag anyways, it would be harder for me not to bring them all.
I currently have 12 boulder deck boxes in the bottom part, another one in the top pocket along with my dice bag, a trade binder in the laptop slot , and I use the tripod spot for my playmat.
I use this backpack - https://www.amazon.com/USA-Backpack-Compartment-Accessory-Compatible/dp/B07BLJBYTM/ref=cm_cr_arp_d_product_top?ie=UTF8
I currently have 12 boulders, a dice bag, a 60 card deckbox with tokens and extra sleeves all inside the bag. I use the tripod spot to hold my playmat and the laptop slot to hold my trade binder. I still have room in the upper compartment to fit another deck or two if I really needed to.
Thats what I use.
I'm currently holding 12 boulders in the bottom compartment. I use the top compartment for my dice and life counter, but I could fit another deck(maybe even two) or something else if needed. I use the tripod spot to hold my Playmat and the laptop slot for my ultrapro trade binder. Only issue I see would be your 4" Binder, thats a big binder to be bringing with you everywhere.
I can fit 12 Boulders in the main compartment, a trade binder in the laptop slot, my playmat in the tripod pouch, and that still leaves the upper spot for my dice bag and another deck or two if ever needed.
Its actually pretty amazing how much I can fit in this backpack considering its not very big all things considered.
This is the bag I use and I love it. https://www.amazon.com/USA-Backpack-Compartment-Accessory-Compatible/dp/B07BLJBYTM/ref=cm_cr_arp_d_product_top?ie=UTF8
I currently have 10 boulders in the bottom compartment and could fit at least 2 more in the top pocket with my dice. It might be too small for you, but I would look at similar bags and see if you find a bigger one that works for you.
Boulders and a Backpack work for me.
I currently have (9) 100 cards deck boxes, (1) 60 card deck box for tokens, (1) bag of dice, a trade binder, and a playmat in this bag. I haven't even used the big top pocket yet, so I can easily hold more decks. Every spot holding a 100 card deckbox can also hold a 60 card deckbox in front of it.
Its still a "Backpack", but its amazing for the price($45). I am currently holding 9 decks in Boulder cases, a trade binder, my playmat, and a dice bag. The only thing in the top pocket at the moment is the dice bag, I could fit more decks in there if I needed to.
Camera Bag off of amazon, holds my dice, decks, play mat, and trade binder with no issues.
This is the one I'm currently using - https://www.amazon.com/USA-Backpack-Compartment-Accessory-Compatible/dp/B07BLJBYTM/ref=cm_cr_arp_d_product_top?ie=UTF8