Apple pay is offered at a l lot of places now. You just have to remember to use it.
As far as msing 10k or 20k...you have 3.5mo to do it. Just between OfficeMax/depot, staples, RA, and WG if you can't do 3k per mo then you probably should not do the MS thing. If you can do 500's and only gonna MS you need 20 gc. There are roundly 15 weeks left in the year. So that means 10 of the weeks you only have to buy one GC each week and 5 weeks you buy 2.
If you have more than one WG in your area you could easily do 3-5 a week.
Or hit staples for 3x200 and then hit OfficeMax for 3x200. That's 1200 right there in <1hr.
If this was 10k in a few weeks I would see the issue...but in 3.5mo it should be easy for almost anyone.