You should also be considering what duties you'll be doing as GSTL. Some stores treat GSAs/GSTLs virtually the same, others its much different. I've also seen stores where the GSTL is mostly hands off and barely has to do much besides coach/evaluate, control equipment locker and occasional checklane reset. Then you have ones where the GSTL is running around crazy having to man service desk even tho their not supposed to, manage self checkout with no kiosk, help at photo (and keep in mind this is the atrocious IGS stores), grab flex fullfilments from back, etc. Or hell I've even seen a GSTL who was on their phone more often than working.
Anyway, point is figure out what YOUR store expects of a GSTL plus what the COL around your area is then talk to them about money. And if they try and five u the BS about a fixed rate don't believe it. Yeah some markets have DTLs who don't like it, but your STL can adjust your pay rate at any time for any reason within a reasonable amount.