Worn out crank
 

Guys, I have a 99 Specialized Crossroads Ultra that has a worn out crank. It's a Nexave cheapie 42-34-24 and the 42 is worn out. On this crank as you probably know better than I do, there are no replaceable chainrings. I bought the bike used and the guy that had it previously eliminated the use of the front derailleur. He put a SRAM twist grip 7 speed shifter on when the original shifter quit working.

Currently, it is still working ok but I wonder for how long. I would like to replace chain, cassette, and crank since it is still a good bike and I plan on keeping it as a commuter, etc.

I live in the flatlands so I really don't need a triple. Any suggestions as to what to do with this bike other than junk it? Could I convert it to a single Chainring in the front and if so would it be cheaper than putting another triple on the front. Also, would it save weight. I'm just curious what the most economical solution would be and what the best solution would be. I have tried to do a search and found that many people are riding 1x? and that seems like a possibility here. Thanks in advance for letting me pick your brains.