Lol! Nice. I love making my own stuff if it seems cost/time efficient. However as a full-time professional TIME is money, and in this case it is far better to just order the pad. I'll leave making it to the kids who have no gigs to do, and a ton of free time.
But as a professional, don't ideas, plots, and gimmicks occur to you that aren't on the market? In such cases, we don't have much of a choice but to make them ourselves. I've had a bunch of ideas for packet tricks and promotional card magic, but the items I need aren't on the market; hence, I've invested the time and money to create them myself.
Time creating new effects, gimmicks, and plots isn't wasted it's an investment.
As you said, it's more cost effective to buy a close-up pad, since they are openly available; however, if you want a close-up pad that's oversized, custom printed (for trade shows), or strangely shaped you could pay hundreds to have one custom made, or you can do the same thing for a few dollars.
Personally, I do alot of customizing either for myself, a client, or for other magicians who don't know how. Promotional magic and "Branding" are somewhat a specialty of mine, so I'm looking at it from a slightly different perspective.