If inexpensive needles and bobbins are a high priority I'd stick with Singer 27,66, 99, 15-91, 201, etc. The needles Joe mentioned that are not to be had above size 14 are MY1014 available new online. If something above size 14 is needed you need to invest in "Boye 18" needles, new old stock for W&W. The black numbered tube usually has 3 needles, size 14, 16, and 18. The red numbered tubes have size 11, 14, 16.
W&W bobbins are pretty distinctive having a bagel shape. D9 bobbins have the hole on each size and the older style #9 have no hole and look similar to the D9.
The "Boye 18" tubes of 3 needles usually sell for around $10. D9 bagel bobbins $10-$20 and the #9 a little scarcer but the same price range.
Sometimes machines can be found with a good supply of needles and bobbins. Occasionally sewers with these supplies will donate if not needed. Sort of wishful thinking but you never know.
Jon