I always recommend the best value to be the font library that accompanies most of the Corel products. It comprises about 75% of the Bitstream type library and has selections from other quality manufacturers as well. This is a good quality and balanced collection which is about 1000 fonts strong and works very well as a core library for your sign business. It even is included with such inexpensive Corel products as Corel Gallery which was a clipart collection that sold for less than $50.00. You may do well to check used software stores in your area or ... very carefully, eBay.
The issue with fonts is not which ones are best for vinyl cutting. You will learn that with experience. The issues are selecting styles that suit the purpose of the design, making them work for vinyl cutting when necessary, and meeting the predetermined specifications of some customers and other designers.
Many of us here will recommend to you that you learn what you can about type and create your layouts without ever stretching or squeezing a font. A font is not just a group of letters in a given style. It is a design that has been planned to convey certain feelings and use of space. Most of the time that design has been conceived and carried to fruition by an individual possessing far more talent, training and experience than any of us here. It, therefore, makes good sense to learn to appreciate the intent of the designer and to use it when appropriate ... AS IT WAS DESIGNED ... without getting all carried away with the power given to us when we purchase a computer and a graphics editing application.
Earlier today we looked at a layout using a geometric sans serif font. Not sure if it was Avant Garde or Futura or something else. It had been stepped on to the point of obliterating the value of the design of the font. That design is crisp and modern, utilizing perfect circles and very even strokes to convey that feeling. Condensing a geometric font immediately takes away the primary feature of the type style. Such fonts are used appropriately with ad agencies, hair salons, art galleries and a host of business types that wish to convey a modern, forward looking image. They are poor choices for automotive repair shops.
I apologize for this diatribe and do not wish anything other than you and others benefit from what I am trying to communicate. Do not take it personally or be offended. That is not my intent.
Below is a showing of the font Avant Garde Medium. The top portion is at normal width. The lower portion is the exact same characters but forced to 75% of their normal width. Compare the two. If you see my point, I'm a happy man.