Just giving him very affordable options.
This knife certainly fills his needs. According to the OP, he's frugal, saves pocket change for purchases like this (e.g. not a lot of disposable income) for his hobbies, and he's looking for options. He's readily said he'll order some cheaper knives from other companies to inspect them. He wants one that opens easily and is rust resistant - which these Coast knives are. He wants an EDC, which can easily be lost. Many folks here, including myself, have lost or misplaced our EDCs. Hence there is value in an easily replaceable item. He wants one between 2.5-4 inches. The knife I recommended fits that bill at 3.3 inches.
What's his intended purpose?
To be honest, I don't tend to abuse my folding knives too much. (I have beaten up some of my fixed blades, though.) I just like having a folding knife on me when I find that a box needs slicing or a fish needs gutting or a rabbit needs cleaning.
These simple chores are childs play for any good knife, including the Coast I suggested. Fillet knives are make from comparable carbon steel, around 440C. Years and years of service with a little TLC that one would do for any blade - sharpen and oil. The benefit of these knives is that he can have a separate one stowed away in his tackle box, hunting gear, coat pocket, glove box, pant pocket, and back back for $50. Add a small sharpening stone to each, and bingo. Still comes in under 1/2 his budget.
@JShirley - if you read that other thread, there's 5 pages of people raving about this deal including a lot of highly respected members here. I'm no idiot, and can determine if a knife is of passable quality. I'm quite impressed by the quality of these knives after doing light work. You might buy one for $7 and see for yourself.
Sometimes what someone wants is misguided, and people are simply separated needlessly from their obviously hard earned (or in this case, saved) money. For the average Joe, there's zero that a $120+ pocket folder EDC knife will do that he can't accomplish with one of the Coast knives for $7.