Cost, Worth, and Value - Defined

I'd like to posit a few definitions in the pursuit of exploring cost, value, and worth.  In a discussion last Wednesday, several of us found ourselves using two of the words to define the third. So, while these "definitions" might sound a little contrived, it's because I'm trying to avoid using those other words.  So, here goes:

Cost - the amount of one's resources which must be expended in order to accomplish an objective (whether to acquire a tangible object, secure a service, or provide a benefit to a third party.

Worth - the intrinsic attractiveness that one may attribute to the above-mentioned object, service, or benefit).

Value - the amount by which Worth exceeds Cost (translated into the same units, if a quantitative evaluation is required).

I'm also posting an example - and later, a little discussion.