I'm using my vouchers to pay for the Wild Tax,
When it comes down to cards as a Wild/survival player, I'm only really buying cards directly from the market if possible at Max level and at a nice discount. The card price gap between new and old cards for me is just too big to justify it. Nice you are happy with your gold foil! The card surely looks nice but is also adding to the power creep problem.
RE: Purchased 25 Copies of Kelan Gains with Vouchers at Splinterlands