I am not sure what a trailer shop or welding shop would charge. This is the type of work I am comfortable to do myself. The drum brakes assembly run from $30 up. So for both sides $60 up for the assembly. Then the hub and drum assembly start about $45 per wheel. I am getting the prices from trailer.com A brake flange can be welded on. They run from $5 to $10. For about $200 for parts. I would guess a trailer shop would charge about $150 or so for labor. Being I'd be in there I'd repack the wheel bearings and maybe look at the spring bushings. The second option is to buy and able with whole brake assembly which runs about $450 from Northern Tool. I think that includes axle, brakes, and springs. Four bolts hold it on. It is something I would do myself. I am in the process of building two trailers. It isn't difficult work it really isn't terribly time consuming.