So on whim I decided to calculate the squares per rouble for each unarmored rig and backpacks. Now for a list of caveats. I almost always rounded up in the calculations. This doesn't account for whether the squares are in 1×3, 2×2, et al configurations. Obviously there's more to the value of any one of these items such as how much space they take up, the configuration, and the aesthetics (I'm looking at you Tarzan rig). Flea market prices can be volatile and future updates can change the barters and prices. I didn't include the flea price for every item. Just assume if it's not there it's either the same price or more expensive.
TL:DR New rigs are pretty good. New backpacks are bad. Cheapo items are good raw value. Flea can generally get you cheaper prices. Barters vary a lot on whether they're better on price or not. Crafts are usually not worth it.
*Flea market price
**Barter items bought from flea
# Craft
Bold indicates best method of acquiring
——————————————
UNARMORED TACTICAL RIGS
Tarzan, 14 – 572 **
Tarzan, 14 – 1,000 *
Umka, 16 – 1,000 *
Azimut, 20 – 1,100 *
Scout, 12 – 1,166 *
MK3, 20 – 1,200 *
Bank Robber, 8 – 1,252
CSA, 10 – 1,300 *
Wartech, 10 – 1,300 *
Thunderbolt, 16 – 1,375 *
Blackhawk, 16 – 1,375 *
Belt, 25 – 1,400 *
Triton, 16 – 1,407 *
Micro rig, 8 – 1,468
IDEA, 8 – 1,500 *
Gear Craft, 16 – 1,563 *
Umka, 16 – 1,687
Triton, 16 – 1,837
Wartech, 10 – 1,878
ANA, 20 – 1,900 *
LBT, 18 – 1,945 *
Azimut, 20 – 1,969
MPPV, 24 – 1,975 **
Scout, 12 – 1,982
MPPV, 24 – 2,000 *
Scav vest, 6 – 2,084 **
CSA, 10 – 2,098
Haley, 16 – 2,193
Gear Craft, 16 – 2,221
BlackRock, 20 – 2,259
Blackhawk, 16 – 2,336
MK3, 20 – 2,413
ANA, 20 – 2,559
BlackRock, 20 – 2,910 #
MPPV, 24 – 3,000 #
Security vest, 6 – 3,334 *
BACKPACKS
Sling, 6 – 341
Transformer, 9 – 445 *
Tourist, 12 – 625 *
Army bag, 8 – 625 ** (Prapor)
Scav BP, 20 – 685 #
MBSS, 16 – 781
Berkut, 20 – 800 **
Scav BP, 20 – 825 *
Duffle, 12 – 1,084 *
Berkut, 20 – 1,173
Day pack, 20 – 1,200 **
Pilgrim, 35 – 1,286 *
Mechanism, 32 – 1,346
Tri zip, 30 – 1,377
Day pack, 20 – 1,381
Gunslinger, 35 – 1,429 *
Tri zip, 30 – 1,467 **
F4, 40 – 1,500 *
F5, 30 – 1,559
Paratus, 35 – 1,572 *
Takedown, 24 – 1,597
Gunslinger, 35 – 1,875
F4, 40 – 1,957
Beta 2, 30 – 2,000 **
Paratus, 35 – 2,031
Beta 2, 30 – 2,467 *
Raid, 48 – 2,500 **
Attack 2, 35 – 2,572 **
Attack 2, 35 – 3,143 *
Mystery Ranch, 42 – 3,510 **
Mystery Ranch, 42 – 4,524 *
Raid, 48 – 4,658 #
Raid, 48 – 5,209 *
————————–
*Flea market price
**Barter items bought from flea
# Craft
Bold indicates best method of acquiring