"维修费用低" can be translated into English as "low maintenance cost" or "low repair cost".
"Low maintenance cost" is more commonly used in contexts where ongoing upkeep and minor repairs are considered, implying that the overall cost of keeping something in working order is not high.
"Low repair cost" specifically refers to the cost of fixing something when it breaks down or needs attention, emphasizing that the expense for repairs is minimal.
Both expressions are accurate, and the choice between them may depend on the specific context or the emphasis you wish to place on the phrase.