Ceramic resonators come in 2 types -
  2 pin  and  3 pin with built in capacitors

In general low frequency 2 pin is 150KHz
to a high of 1.5MHz
each extreme adds to cost.
In this range, 455KHz is probably lowest cost.

then another type covers 1.5M to 25 or 50MHz
available in 2 or 3 pin.
Again, the extremes cost the most.
4MHz is pretty inexpensive

I think both styles come in SMT but I'm not sure of cost.

Available from 4 main companies that I know of:

Integrity Technology  408-262-8640
  least cost, only deals in large quantities (5000 or so)
  I saw that there is a low quantity "dealer" in Canada

AVX/Kyocera  803-448-9411
4MHz with caps is KBR4.00MKS
  I get these through Kent Elec. for $.26 in 100s
455KHz without caps is KBR455HKTS
  I get these through Kent Elec. for $.20 in 100s

MuRata  404-436-3030
  about .35 for equiv 4MHz part

Panasonic   most expensive, available through Digi-Key  (800-digikey)
.58 in 100s