I can't answer the guitar-orientated question but a search at http://download.cnet.com/ for guitar lists some shareware and freeware products that may be worth downloading for evaluation. With refrence to the CakeWalk range, it looks to me as if you would have go for Guitar Studio 2 to get the tab features. Cakewalk list this product at $249.
Whith regard to comparisons, NoteWorthy always seems to come off favourably and I would susect that it is one of the best in the $50 category. Another roduct that I would like to hear more feedback on is Melody Assistant which is $15. The biggest attraction with Melody Assistant seems to be the mumber of file formats it can handle.
I use CakeWalk pro audio 3 which is quite old but I find it much easier for arranging MIDI's than Noteworthy. The current version, Pro Audio 9, is $429 but even their "entry level" Home Studio 9 is more capable than mine and costs $129. This is still quite a step up from $50 but it may be worth considering by those who have a little more money to spend.
One important note, the strengh of the versions of CakeWalk I have used lie in their MIDI editing capabilities. They provide a very easy user interface for dragging notes onto a staff, and adjuting MIDI features like track volume, pan, chorus, reverb, temo changes, etc. but are geared towards the MIDI standard which as John has mentioned does have limitations in some areas and I have seen notation (including lyrics) produced by programs like Noteworthy (using it's own file format) that are simply impossible to produce using CakeWalk. The way things stand at the moment, it seems to me that a user has to be clear on what their main aim is, ie. produce notation for printing or to be played as a MIDI sequence before making any software discisions.
John, I would be interested in hearing your (or any other) comments on the MIDI standard but I am not sure where to begin in starting a new thread. Is there a new standard being proposed?