What Trailer Tire or Tires?

Had a blow out this weekend and need to replace the tire. Called up my local tire shop and they said $95 to replace it with the original Goodyear Marathon. I also got a price on Carlisle tire for around $70 and (I think he said) a Towmaster for $55. I don't have rims and my wheels are just you standard run of the mill chrome trailer wheels. Would you go ahead and replace all four or wait and replace one at a time as they go out? We don't make long trips and the lake is a couple miles from the house. Second question is does brand really matter? Is a trailer tire just a trailer tire and you pay for the name on the side? Any horror stories with certian tires? Got a spare on now, so I am in no hurry.