I got over 40,000kms out of the stock chain and replaced it out of preventive maintenance. Clean it regularly and lube it religiously every 700kms or so and you are good to go.
For the new chain I got a Regina endless and did the swingarm drop, I had not access nor chance to pick up a riveting tool locally and it would have cost me well north of $65 to have one shipped in. I have been beating the hell out of the new chain and it is doing fine. Doing the swing arm drop gives you a chance to get some well needed lube into the pivot points and is a plus side of the job. Most people ignore lubing the swing arm because their is no grease nipple. Motorrad are as cheap with grease on the swingarm as they are with the wheel bearings.
If you go the route of a rivet chain you are looking at around $175 for a chain and tool and sprockets, I would imagine.
If I can get 40,000kms out of the Regina I'll be happy, however I will likely sell the bike well before that. It should be possible to get well over 50,000kms out of a good set of sprockets and a quality name brand chain if you do the maintenance. I ride only on 3rd world roads full of tope speed bumps and it is constant acceleration and deceleration and rough surfaces with the odd very high speed stretch of toll highway. It's "no country for old chains".