I can easily get 4000 miles of life on a chain (based on careful measurement) and never take it off the bike to keep it cleaned and lubed. It takes about 1-2 minutes about every 2-3 days to lube it and wipe it down on the bike. My chains always look immaculate.

I wouldn't pay a nickel for a master link. In fact, if you are using it to remove the chain to soak it in solvent (and remove the lube from the most inner surfaces of the chain where it is needed most), the master link has done you more harm than good and cost you extra money on premature chain replacement.