One of the most heavily used tools in your shop will be your table saw. It is absolutely essential for ripping stock to size, working with composite material (like plywood and MDF), and venturing into the world of wood working jigs. Budget is a limiting factor in a $500 build, but at $150 it is hard to pass up adding this Craftsman saw to your shop - even with limited funds.
On the 100/300 grit combo stone: absolutely, positively NO – and I’m a woodworker by training who sees sharpening of tools as a means to an end and not as a religion. DMT bench stones are soooo cheap in the US (they cost as much as 3 times as much in ROW) that you should not waste (expensive) time with Chinese carborundum stones or EZ-Lap …err … junk.
Ok, the leap from $1,000 to $2,500 is a big one. I certainly didn't make it at one time. It took me years. But I know folks that decided they wanted to get into woodworking and dropped at least $2,500 getting themselves outfitted. When you do make the jump, the thought process becomes much less about making sure you can get the job done and becomes more about having quality tools to get the job done.
There are and they are considerably cheaper. I found a pair of glue brushes on Amazon for less than half the price of a singles dedicated glue brush. I tested them out on a recent gluing and they work well for spreading glue and getting it into dovetails and mortises. When you are done you can either run the brush underwater to clean it or wait until the glue dries the pluck it off the bristles with a few easy pulls. The glue comes right off the silicone bristles.
The next important hand tool for the woodworker is an accurate tape measure. Get a retractable one that is at least 25 feet long. Any longer than that, and you start having problems getting it to roll back up. Since measurements on large scale projects can be very susceptible to even the most minute measurement variations, you’ll want to make sure the “hook” or tab at the end of the is firmly attached, with no give. When they get loose, you’ll have as much as 1/8” variation in your measurements. This can add up to some severe accuracy problems in the long run.