From Brotato Wiki
How to win on Saver
This is my personal take on how to successfully play Saver at the highest difficulty setting (Danger 5).
The Saver is all about handling the shop well. If you figure that out, the character becomes much easier --- if you have the mechanical skills to handle a squishy character at D5.
Padding
Obviously the strongest item on Saver is Padding, the character's own unlock item. Because Saver accumulates a lot of materials anyway, to scale his %Damage, Padding will be extremely effective, turning him into a monster tank. Even early on, the item will easily add 15 max HP or more, and it will scale exponentially, along with your damage.
Unfortunately, Padding is a Tier II item, and therefore not a guaranteed find, especially not early in the game. Chances of finding the item can be increased with Luck, which is a useful stat anyway for other reasons. However, you can never be certain to even find the item at all, or find it early enough to help you (for example, before the first elite fight).
Having said that, if you find a Padding early enough, your chances of winning increase dramatically. So if Saver is one of the characters that you are still missing a win on at your chosen difficulty, just look for this item and success will eventually come.
In this guide, I will assume that no Padding can be found, and point out how to win the game without this advantage.
Exponential money (and damage) increase
The key to play Saver well is to understand how dramatic the effect of the Piggy Bank is (your starting item), and what that means for shop purchases.
The Piggy Bank multiplies your money by 1.2 (+20%) at the beginning of each wave. Since it is multiplicative, this is an exponential process, at a staggering rate. And this process also applies to your %Damage, due to Saver's passive ability.
To get an intuition for how strong this is, observe that any amount of money held more than doubles after only 4 waves, and after 10 waves it has multiplied more than 6 times.
To drive the point home: any money that you simply hold after the first shop will get multiplied by about 26.6 by the time you enter the wave 19 shop. So if you just kept the ~70 materials that you usually have after the first wave, this would become almost 1900 materials by the last shop (and +75% to damage)!
It is therefore crucially important to keep as much money as possible, for as long as possible, because no item purchase can compete with this staggering growth process.
Unfortunately, it is not possible to play without ever spending any money, since you need weapons and some items in order to even begin to deal damage, and to survive. Your %Damage means nothing if there is nothing to scale off...
So there needs to be a balance between saving and spending, and when to do which. This is what makes Saver very difficult.
The Gun setup, and why it is good
So what is a good strategy for itemizing Saver, then?
Saver's weakness is the highway robbery that happens in the shop, where he has to pay +50% more for everything (except rerolls). This means that many items are not economical, and you can not rely on the shop to cover your needs.
However, Saver does not pay extra for rerolls, and he gets the same level upgrades as other characters. He also does not have a penalty to his XP gain, and he does start with some harvesting, which provides extra XP (and money, of course).
Having normal reroll prices means that rerolls are relatively cheap on Saver, and can be used more liberally, so fishing for stats during level-ups is more viable on Saver compared to other characters who do not have the economic advantage of the Piggy Bank.
This is why a gun-based glass cannon build works well on Saver. Such a build wants a lot of Ranged Damage and Attack Speed, and these stats are difficult to find in the shop anyway, which means in this aspect Saver is not much worse off than other characters that can use the shop normally.
So we want weapons that are easy to find, do not require upgrades to become good, and scale well with Ranged Damage and Attack Speed. We want to be ranged, to stay safe, and be able to farm safely.
That means Revolver, SMG, Double Barrel Shotgun.
We start with a Pistol, then get as many of the above as quickly as possible, plus some other essential items. When we level up, we focus on Attack Speed and Ranged Damage.