K-Tool International has a bunch of grease fittings in their catalog, usually 10 per package. You can find them on amazon, but are no where near the price of the Harbor Freight fittings. As an added bonus, K-Tool says their fittings are Made in the USA, if COO matters.
KTI-04319...............Grease Fittings Metric 10MM 45° Elbow
KTI-04320...............Grease Fittings Metric 10MM 90° Elbow
KTI-04318...............Grease Fittings Metric 10MM Straight
KTI-04313...............Grease Fittings Metric 6MM 45° Elbow
KTI-04314...............Grease Fittings Metric 6MM 90° Elbow
KTI-04312...............Grease Fittings Metric 6MM Straight
KTI-04316...............Grease Fittings Metric 8MM 45° Elbow
KTI-04317...............Grease Fittings Metric 8MM 90° Elbow
KTI-04315...............Grease Fittings Metric 8MM Straight
KTI-04309...............Grease Fittings SAE 1/4-28 45° Elbow
KTI-04310...............Grease Fittings SAE 1/4-28 90° Elbow
KTI-04311...............Grease Fittings SAE 1/4-28 Long Straight
KTI-04308...............Grease Fittings SAE 1/4-28 Straight
EDIT: I did not look hard enough, but finally found their large assortments:
KTI-00023 - 60-piece Grease Fitting Kit (SAE)
KTI-00024 - 90-piece Grease Fitting Kit (Metric) - (Found on Lowes Online, and Summit Racing for $59.99)