Well...it sounds like you know you will appreciate the difference. If you cant convince your dad, you are outta luck.
You could just tell him you will use the money on piercings and tattoos and beer instead! He might change his tune.
Or you could go off into the "world" of great, inexpensive knives like Moras and Opinels and Tramontinas and such.
Best of luck to you, whatever you decide to do!
Ditto on all counts. Spydie99, you sound like a great kid: you work and save, you're responsible, your postings here are thoughtful and respectful (more than we can say for some members 3x your age), and at 13 you actually have reasonable and respectful conversations with your father about spending and dating and all manner of things. I didn't 'absorb' all of those lessons until much later, and my father might argue I still haven't. As a father of two now, I can only hope my kids are like you when they reach your age! The fact that you've come to appreciate Spyderco over Benchmade at 13 speaks to a level of 'knife maturity' that I didn't reach till my mid-30s, and that some others here will never, ever achieve.
But to pick up on Marcinek's last suggestion: this might well be something you already know but the difference isn't just between bad, less expensive knives and good, more expensive ones. Obviously you know there are plenty of crappy, pricey knives; but there are also really good inexpensive ones. If you haven't already done so, for $40 you can pick up a Vic Alox SAK -- Farmer, Electrician, or Pioneer -- and an Opinel #8. Opinels arguably have the most comfortable handles on just about any folder, regardless of price; and SAKs are just downright more practical and functional than just about any folder, regardless of price. Quality control and warranty service can't be beat, either; Victorinox's service dept doesn't quibble with its customers over what might constitute 'abuse.' Opies and Vics won't replace your more expensive knives but you might be surprised at how frequently they make it into your 'EDC rotation.'
Last but not least -- addressed not necessarily to you but to anyone thinking about how to finance a college education for a child or him/herself: I fully agree with those who encourage you to go to a four-year college/univ. but, respectfully, I have to disagree with some of the advice regarding cost and financing given here. However commonsensical it sounds -- in-state public as the best and least expensive option -- it isn't necessarily true. Depending on your academic profile and family's financial situation, a private or out-of-state public institution might be better and less costly, in some cases far less so. Unlike some things I might say about knives, I actually know what I'm talking about here -- I'm an associate dean at UC Irvine, which is a 'research 1' university, top 50 overall and top 20 public univ. Just some brief examples: If you're a Calif. resident whose family earns below the state median $80K and you are admitted to any Univ. of Calif. campus, with few exceptions your tuition will be fully covered by Cal and Pell grants, with the difference covered by univ grants (look up "UC Blue and Gold Plan"). You may still need loans or pay out of pocket for room/board, living expenses, books, entertainment, etc.; but tuition will be covered. If your family earns less than $150K and you're admitted to Harvard or Yale, your tuition to either will be waived. In other words, if you're a CA resident whose family earns $140K, your college ed would cost vastly more to attend UC than to attend Harvard. If your family earns $200K, given the 'sliding scale' approach used by many Ivy League and other elite private schools, a Harvard or Columbia will still be less costly than a UC, whether Berkeley, Irvine, Riverside, Davis, UCLA, etc.
Two family examples: my cousin's daughter (Wash. state resident) is an undergrad at Vanderbilt on a partial scholarship and is paying about 3/4 of what it would have cost her to have enrolled at U.Washington. My nephew from Hawaii wasn't offered a dime of support from U. Hawaii but is attending U.Missouri on a full scholarship.
Moderators -- sorry to carry on WAY OFF-TOPIC but I just wanted to provide a corrective to, or at least different perspective for, partial or misleading information that could turn out to be far more costly for a family or individual than the difference between a Spydie Tenacious and Paramil 2!
My main advice would be for anyone interested to speak directly with academic counselors (not just financial aid counselors) at colleges/univs. you or your kids may be interested in. They can help to match funding opportunities with your academic interests and financial situation.