That's what the 0.26% covers, the additional revenue from hiking the price.

Say your revenue before this tax was $100, just to use easy numbers.

• A flat 5% increase: 100 x 1.05 = 105. New revenue taxed: 105 x 0.05 = 5.25. $0.25 in the red.
• A 5.26% increase: 100 x 1.0526 = 105.26. New revenue taxed: 105.26 x 0.05 = 5.26. Back to the old "real" revenue.

Of course, there's nothing stopping a company from hiking prices higher, but hiking by 5.26% is the absolute minimum to break even.