how i trace drawings
1) scan or photograph drawing
2) import into Cad program as a image
3) on another layer draw a red line of a known length
4) scale image into drawing so image matches line of known length, for example if something on drawing image is 12" then scale image until it matches 12" reference line
5) adjust image angular rotation if off. sometimes image is not perfectly horizontal and may need a degree or 2 rotation
6) on a different layer with red lines, trace over scanned image with red lines, arcs, etc (you can create red lines, arcs, etc accurate to 0.0001" easily in dimension and position on drawing of course) and then, you may make scanned image layer invisible. then the red line layer can have it's color changed to black if desired. the reason it was red is it can be confusing sometimes telling new black lines from scanned image black lines. the 2 colors makes it easy to tell new red from old black
in general it does not cost money for new equipment to trace a drawing. it is vastly faster and far more accurate to use a mouse and a keyboard to create lines, arcs, etc of exact dimensions (0.0001"). a drawing on paper is for reference only , it's use is only to make sure everything is traced by using red lines covering black scanned image lines.
you can buy equipment if you want, but my experience of over 3 decades of work is it is a waste of money and not very precise.
........ a tablet for drawing / like painting or creating a charcoal sketch like a artist uses is a different matter. if you want a tablet to be an artist thats up to you but you do not a need it to trace a drawing precisely.