I dont think its neccesary to spend 200£ to fix the mid. Your arms look fine so no need to blow money on those. I do have spare nip rear arms from speed model.
I also make my own arms and i do have the fronts.
All you need are belt covers..gears and body. If you want to drive this car best not to spend money on new parts. Sometimes used parts lots appear on ebay for cheap. You can go for those. Heck sometimes buying a used car is way cheaper.