Yeah, that's what I meant by upslotting. A setup for the affix I gave earlier would look like this:

Spoiler!


Upslotting can be cheaper, but not always. It's generally not recommended to upslot to 5s without a +10% boost week since your maximum chance gets reduced to 90%x5, which won't be very easy to pass. +10% affix boost weeks aren't too common, they usually come around once or twice a year.

Adding Stamina III to that affix would be a bit difficult since Guranz Soul would start to get expensive at 4-5s. At that point I'd just recommend switching to Ragne Soul at the cost of some pp and doing something like Ragne/Tech III/Spirita III/Stamina III/Latan Fever with a same-slot affix. That should be within your budget considering these affixes are relatively cheap.