Checking through the "sold" listings on eBay most older (and tired looking) manual grinders seem to be going for around $800.00. The larger automatics go anywhere from $1,200.00 to more than $8,000.00. In our area there are currently several listed on Craigslist. The nicer manuals are listed in the $800.00 to $1,000.00 range, while the poorer looking ones are listed in the $500.00 range.
Like anything else the price is dependent on location, demand, and condition. Being in the rust belt the prices in our area seem to generally be lower than in areas with less manufacturing or more demand for used equipment. Back in 1012 I purchased a Sanford MG 612 manual grinder. It was in excellent condition and came with several assorted wheels. The price at that time was slightly more than what you offered for the Brown & Sharpe.
Before making a purchase I would check in out thoroughly. If the ways are worn, the spindle bearings need replacement, or there are problems with the motor, repairs could easily run more than double the cost of the machine. As for factory support, most of the "maintenance" components are off the shelf. Motors can be rebuilt or reconditioned, but it's not cheap. About the only things that aren't available these days are castings, table parts, and ways. On many machines the ways are replaceable, but you'll have to either make them, or have them made. Again not cheap.
This is the grinder I purchased for about the same price as you offered. It looked exactly like this when I purchased it. It didn't require any cleaning, reconditioning, or new parts.
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