So, if the "former scout" determines the boy isn't going pro, I guess the parents pack it up - no more lessons, no showcases, and no baseball? Or, if the "former scout" determines the boy has pro potential, the parents decide to up his commitment? As another poster noted, evaluating pro potential and college potential may not overlap. Is the "former scout" also a former RC or college HC? And, why isn't the "former scout" also teaching?
As to the point that observing the entire "game" a kid brings is better then the showcase velo, the game time pop, or running out an actual ball, that's nice - AND exactly what a scout does before a player is drafted. No scout who remains employed long uses pure showcase numbers in determining if a kid is drafted. Showcases can put a kid on the radar; but a single look in that format doesn't get a kid drafted. My S was drafted out of a very small non-baseball HS as a smallish LHP; scouts attended EVERY home and away game his senior season (he did no showcases and only played scout ball as travel); they watched whatever scouts watch to define his heart, head (I have no clue what they look for), and game. My point is, even a late round throw away pick was seen in depth.
Perhaps you are simply offering a business plan in which a former pro scout (which is not part of the developmental personnel employed by each organization) draws up a long term written plan for the kid based upon repeated in depth views at actual games. To me an expensive and uncertain approach - for example, will the scout be familiar with the unique physiology each player has (fast arm, short arm, stiff hips, super loose, etc) and of which the kid's PC's are aware; or will the written report be generic (like a horoscope or most camp evaluations).
I used the money to get S a personal coach who did the exact same thing ("evaluate") AND teach AND mentor, AND who used his contacts to various colleges, AND who alerted local scouts AND who coached the local scout team. And, for less than the idea presented here on a per diem basis. Since in my area there are several such people, I don't see the demand in San Diego.
I guess if a family has unlimited money, why not waste a bit - playing on fear, worry, paranoia, and insecurity can actually bottom a business plan.