Amazon offers the PNY Turbo Performance 64GB Class 10 microSDXC Card, model no. P-SDUX64U190-GE, for $24.99 with free shipping. That's tied with our mention from four weeks ago as the lowest total price we've seen. (It's the best deal today by $5.)
Update: Note that this item is temporarily out of stock, but can still be ordered at this price for delivery when available.