The advantage of Sign Tools and Smart Design is the macros (automated effects) that can make things very easy. None of it is necessary, but if a person is new to Corel, it helps eliminate a lot of the learning curve, and even helps an experienced user save time.
I mention Smart Design instead of CoCut, because CC is a "bridge", where as Smart Design has the "features". A little known fact is the Smart Design WILL split the cost into three payments and always has "wiggle room" in the pricing.
We own neither, but have looked at them thoroughly, since their beginnings. I still think about Smart Design, because it is sooooo much more capable than the Sign Tools, and it would allow for me to have someone not as experienced in Corel (like the wife) do many things that I have to. (That goes both ways, when the either "half" does all of the layout and design, and the other is allergic to it.)
The biggest hang-up is people try and compare it with something like Flexi or Signlab, which are very good but they are not geared towards having pre-installed macros (automated effects), which greatly benefit the newer user.
As for Sign Tools, the effects they offer are very easy to use, and the those macros are very easy to setup and save. A cheaper alternative would be to get the book Learn Corel Draw in 24 Hours, by SAMS Publishing. One day of reading will give you what Sign Tools does, except for a cutting driver, which is nothing but an HP-GL driver, available anywhere.
If you are just looking for a cutting driver, another little known fact (never told by equipment dealers) is that schools do not/cannot afford sign software. They primarily use programs like Arts & Letters, and the generic HP-GL drivers.
If you are intent on spending some money (absolutely nothing wrong with that), call Smart Design and tell them that you are aware that they will split payments and that they have wiggle room (which often results in them throwing a bunch of decent clip art - that would normally cost a few hundred.) You will not regret it, and definitely will profit from it!
I hope this helps.................
George