The 328 takes the flat cams. Very common I guess, but I don't see them anywhere near as often as I do the top hat cams. The 328 is a bit noisy, but it's also all metal. No plastic inside. I've got at least one of every flat cam and they are nice to make designs for. The original accessories kit came with 8 cams I believe. Shopgoodwill.com has the cams off and on.
I agree that $90.00 is too much for a complete set. But outrageous prices are common there. $10.00 is also a bit ridiculous on the low end for a complete set. They are not that common.
Oil that 328 up and give it a chance, you might like it.
Joe