Honestly, regular 300m is a long shot for floor 80 if you sell things ragial price today. As an ET looter and seller for my friends, you're probably looking realistically at around 200-250m per ENTIRE ET run on a decent day. It's probably more if we do 3 run per week, but people don't have that much time on Sunday. Also I have 9000 weight limit with cart looting everything on sight that carries decent to good value. Selling both trash and treasure, it is usually around 200-250m for entire run, given there are no crazy cards drop. There are days we barely make more than 100m total. There were times when MvP card drops and loot go into the billion. It's all a gamble really .
As for supplies, it varies a lot per person. You can probably estimate by looking at your AB damage, then divide by total HP of all the MvP have, add some extra bomb to offset the boss's defense. That should give you some good idea how many bombs it may take per run. You also may need few tokens if you decide to solo.