Deruvian,
Putting on one tire could cost you a lot more than 135 bucks.
The accepted wisdom and factory recommendation is that you replace all four, and put on replacements that are all the same, i.e. no Yokahamas on the front and trying out new Pirellis on the back.
The reason for this is the need to have all four tires the same rolling diameter to avoid putting strain on the 4wd diffs. Personally, I have replaced two tires only with no known ill effects, but it was when the the full set was pretty new due to pothole blow-outs.
You could try adjusting the rolling diameter by the tire pressure if the new tire has a lot more tread on it. See they are at correct pressure [34F, 30R] and measure the rolling radius by accurately measuring how far from the ground the top dead centre of each wheel rim is. They should be all exactly the same value on level ground. If your new tire is showing higher due to the extra tread depth, reduce the air in it until the height is the same as the other three. Your rolling radii should now all match, and you will not damage the differentials.
Joe
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