just my opinion: if you plan to stay in silver league level due to archions, next set I would say use some of the seasonal glint and do some gf rarity draws, you can also do max reg foil draws and get a decent amount of gf in the common/rares to get GF silver leveled reward cards what I will consider cheaply. If memory serves me correctly its 60k glint for 300 commons and 75k glint for the 100 rares and with some luck you would have a decent jump on the gf and probably have the reg foil really quickly.
once the new rw cards are here, the unlock costs goes to 10x for the REB ones, making getting what you might want now cheaper and when it does, you will still have use of the Reb rw cards until a new set is released in like a 1.5 years. you can probably pick them up very cheaply from other players like myself, who is planning on making any single bcx cards available to anyone for just unlock costs.
RE: Am I Making the Right Decision on Reward Cards