I have a tiny job nowhere near a plugin I'd like a cordless grinder for. I'm a proponent of buying good tools, but the price for a good cordless grinder is too much for my near single use. Anyone try the new Harbor Freight cordless Chinese wonder?

I have my real tools and I have my Harbor Freight tools. Both serve a purpose.

If I know I'm going to use it for one job or two, I'll pick up something from Harbor Freight (like a pneumatic roofing nailer). If it's something I'll be using on a regular basis, I'll spend the money on a higher line tool (I have a bunch of Milwaukee 12V and 18V tools).

When I was racing, I would bring whatever specialty tools I might need and my Harbor Freight tools hand tools. My good tools would stay in the shop.

For a small job and/or limited use, Harbor Freight stuff can come in pretty handy.

Just consider the HF tool as the rental you don't have to return

I understand what you are saying, but you may find an angle grinder to be much more useful than you think.

I have the DeWalt 20v and use it all the time for everything from cutting metal to sharpening mower blades.

I agree with MNSIG above.. you'd be surprised once you get a tool how it will be needed afterwards....
A cordless right angle grinder with a thin cutting blade will cut just about anything faster than just about any other tool... wire, cable, steel, locks...

https://www.youtube.com/watch?v=QxX_hnCz6G0

you might be able to rent a great one for the same price for the day.

some of H.F.s tools have good warranties,
maybe ask them about it

 
Do you already own a cordless set up, such as a drill and impact set. If so, look at that brand for a grinder and buy it sans battery, a bit cheaper, and use the batteries and charger you already have on hand. This is the route I took, already owning the Bosch set with two extra batteries.
 

It should be fine for the job. I generally stay away from their power tools but I've heard good things about their 20V line. Personally, I have a mix of Porter Cable, Bosch, and Makita for power tools.