Pretty much all you do is get a VPN and switch to something like Brazil where the prices are a bit cheaper.
US Brazil
60 Primogems-0.99 $ 60 Primogems ~ (0.69$)
300 Primogems-4.99 $ 300 Primogems ~(3$)
980 Primogems-14.99 $ 980 Primogems ~(9$)
1980 Primogems-29.99 $ 1980 Primogems ~ (19$)
3280 Primogems-49.99 $ 3280 Primogems ~(32$)
6480 Primogems-99.99 $ 6480 Primogems ~ (65$)
P.s I used urban vpn to do this its free and does the job.