The Sears grinders aren't all that bad for the hobbyist. If you do flat grinds, saber or convex grinds on your knives, a Sears 2"x42" is up to the challenge. I know because thats what I use. I do many smaller neck size knives on a Sears 1"x42".

Actually, I'm finishing an order for 10 neckers now in 440-c and the bulk of that work(finish profiling and bevels) was done on the smaller grinder.
Granted, a larger 2"x72" grinder would ROCK, but small time and/or hobbyist knifemaking is to a large extent all about using equipment, tools and materials that are readily available.
I started knifemaking as a hobby about 1992. (It is now starting to pay off as I'm in the process of going into business.) Prior to that I had
zero experience using machine/wood shop type power tools. I read as many how-to's as I could find at the time and basically taught myself how to use the equipment and tools of the trade that I acquired from pawn shops, thrift stores and places like Sears and Lowes/Home Depot.
The going can be slow at times but persistance begins giving dividends when you put the finishing touches on a knife you made all by yourself.
Just don't expect your first knives to be Loveless or Ron Lake quality. You must understand that to a great extent good home made knives come from patience, gathering and implementing information on materials and methods and practice, practice and more practice.
Knifemaking is a fluid and dynamic endeavour. You must be willing and have the ability to adapt to the demands of this hobby. You'll need a good imagination and a good deal of ingenuity because sometimes things don't go or work the way they are intended to and you'll have to be creative in your problem solving.
Then there are the little nuisance things like burned fingers, belts that occasionally seperate violently and sound like a gunshot in your face, the most dangerous piece of equipment in your shop(the buffer) occasionally grabbing a knife from you and throwing it willy nilly around the shop or at you, splinters out the wazoo, uneven grinds and grinds where you don't want them and did I mention it is one of the dirtiest hobbies this side of pig wrestling?
But you will love every filthy minute of it after you finish that first knife and think to yourself "I can't believe I actually made this...WOW!"
It is probably one of the most dangerous and gratifying hobbies one can get into. And, who knows, eventually you may even get paid for doing it.
If you are thinking about trying knifemaking I suggest you invest in a couple of Wayne Goddard's books "The $50.00 Knife Shop" and "The Wonder of Knifemaking". They are a valuable resource for the myriad of questions that you'll soon find you need the answers to and the books have LOTS of tips on how to do things you may never have even suspected needed doing when making that first knife.
Good Luck!
All the best,
Mike U.