It's the parts that will get you. The gears can be $150 each new if you can find them... Try used, or look for an entire used lower unit... (and it's a clutch dog)
watch ebay for a lower unit. the complete gear set if you can find a new one, will run $4-600 for parts. look at ebay# 150136363099 it may work, you will have to verify shaft length, etc. or use the gears.