The price of the phone increases by 21% and the price of the repair also increases by 21%.
Of course if the price of the new phone before tax is higher than the price of the repair before tax the same will be true after tax.
And if the price of the phone is 200 and the price of the repair is half of that it will still be half of the price of the phone after tax. But if taxes are 0% it's either 200 or 100 for the repair and if taxes are 900% it's either 2000 or 1000 for the repair. The repair may be prefered if you cannot afford the difference but it will still be half the price of the new phone.
Of course if the price of the new phone before tax is higher than the price of the repair before tax the same will be true after tax.
And if the price of the phone is 200 and the price of the repair is half of that it will still be half of the price of the phone after tax. But if taxes are 0% it's either 200 or 100 for the repair and if taxes are 900% it's either 2000 or 1000 for the repair. The repair may be prefered if you cannot afford the difference but it will still be half the price of the new phone.