In my opinion, you need to be WAAAY more specific regarding your requirements. Doors and drawer fronts vary considerably in design and cost to manufacture. A door could be as simple as a flat rectangle with rounded edges, or a panel design. Hardware (pulls and knobs) also varies considerably in quality and price.
Imagine if someone asked, "I need a car body. I want to paint it myself. The prices I have seen vary W-I-D-E-L-Y on car bodies, ... Any suggestions on who to use for a great price?"
I recommend that you invest time and effort with local cabinet makers to learn more, figure out what you need, and try to understand what makes some sources cost more than others. The people here live all over the world, and you are asking for something that is probably best obtained from your local area.
It isn't easy, because some cabinet refacing companies have slick marketing hype with elaborate demonstrations, free meals, fancy showrooms, and high pressure sales tactics where they phone you all the time to invite you to special, "exclusive" events that aren't very exclusive. The cost of all the sales and marketing must be factored into their pricing. One thing you must learn is how to separate slick hype pricing from quality product pricing. Once you know what you really need, want, and can afford, it should be easier.
Shopping for doors and drawer faces takes real work. There are no shortcuts.
That's my 2 cents. Others here may offer more helpful thoughts.