For small parts, we use a small diaphragm pump, like you would use as a small compressor for an airbrush spray setup. Just use the intake port.
You can usually find these used in the $30 range. The ones sold for airbrush spraying don't usually have an intake port, but at least on one of mine, it was easy to figure out where to punch a hole through the head and tap it for 1/4 NPT.
The one I bought last was a surplus medical diaphragm pump. These are usually in the $50 range, and usually come with a gauge and sometimes even a needle-valve type vacuum regulator.
The only one I see listed on ebay right now is new, for $85. Here:
The other option is a cheap vane pump. These are often used in the HVAC industry for leak checking and charging refrigerants. They seem to be in the $100 range new, and $50-ish used.
Hope that helps.
"The Magic Carpet" Flying since Sept. 2009
1/4 share in 1959 C-182B (tow plane)
LS6-15/18W sailplane SOLD
bought my old LS6-A back!!
VAF donation Dec 2022