The first thing I was told is to get myself a good 2x72 belt grinder.
The Coote belt grinder is the best grinder hands down for the money in my opinion and lots of others. You have to buy a motor and some pulleys for a few extra bucks, but it'll run you at around 500 bucks overall.
As far as other equipment goes....A metal cutting bandsaw from Harbor freight is nice to have and costs about 150. A small benchtop drill press is another essential. On sale at grizzly and harbor freight for 50-100 bucks. You'll also need some hand files, a good hacksaw, a good vise, handle materials, sandpaper, drill bits etc. and a workplace to put all of this stuff. You could send your blades out to heat treat, or if you wanted to, you could do it yourself with a small forge you could make yourself, or buy for about 200 bucks.
expensive hobby... but fun!