Cat fracture surgery costs broadly what dog fracture surgery costs: simple repairs from around $2,000, standard plating $5,500 to $8,000, complex work beyond that, plus the emergency stabilisation invoice that usually precedes it. The cat specific difference is the strength of the amputation alternative, at $1,500 to $4,000.
Cats are so good on three legs that for shattered or complex limb fractures, amputation is not a sad compromise but a genuinely reasonable choice: one surgery, one recovery, and a cat that runs, climbs and lives entirely normally. Any quote for complex feline fracture reconstruction should sit alongside that alternative, priced honestly.
Also cat specific: many feline fractures follow car accidents and falls, so the first invoice covers chest x-rays and stabilisation before anyone discusses the leg. That sequencing is correct medicine; broken bones are rarely what threatens a cat's life, but the injuries that come with them can.
Send what your vet said and quoted. A veterinary surgeon reads it and comes back to you with what they can do and what it would cost, before you pay anything. A written second opinion is from $250.
Send the case, hear back from a surgeon with what they can do and what it costs, and only pay if you go ahead.