Generally, most PSUs are very specific to the device. Some TVs have the same unit in a series with different screen sizes or functionality, but then it is the same board so the price is the same. Finding a different, cheaper PSU is mostly not possible. What you might do is to open it up and carefully inspect the capacitors of bulging units. Any convex top is an indication of a failed or failing cap. Those can be individually replaced at a far cheaper rate.