You could probably get more for much less shopping surplus...for example (all from Electronic Goldmine):http://www.goldmine-elec-products.com/prodinfo.asp?number=G17169
- Container of LEDs (~200) for $4.95 USD, vs 20 for $6.99 @ Sourcehttp://www.goldmine-elec-products.com/prodinfo.asp?number=G17170
- CDs Cell Surprise (100+) for $5.00 USD, vs 5 for $4.99 @ Source
There wasn't a good example for the matched pair IR kit @ Goldmine or All Electronics (although you might find something in this box: http://www.goldmine-elec-products.com/prodinfo.asp?number=GP23
), but I bet you could cobble something together from either or both that would work well for much less than what the Source is selling them for.
Note also that I am not saying you have to buy 200+ pcs of something, either - Electronic Goldmine (and All Electronics, and others) offer smaller quantities of certain parts, but in surplus, things get stupid cheap the quickest with a large number of parts. I once picked up a couple of these from Goldmine:http://www.goldmine-elec-products.com/prodinfo.asp?number=G9321
...and was very pleased at the amount and types of "floor sweepings" I received (I actually received some very nice parts in those assortments - a handful of them easily were worth what I paid for the box).