Hi Rob, You can find both frets and fret wire (by the foot) at ebay.com and some of the folks here also sell both as well. Be patient, someone will let you know here usually in a short period of time.
Hi Rob, Frets by the pound or length are available from stewmac.com. They also have a free fret computer which you will need, and nice sets of economy tuners. Everything you need you can find there. Richard in Tennessee
If you're looking for just enough for one build and you have a guitar shop that does repairs close by, they will usually sell you a "stick" (2 foot) for fretwire which is ususally enough. Anything up to $ 5 is fair since you don't have to pay freight. It will also give you a chance to ask about used tuners.... repair shops often have a box of "take-off"s that they will sell you a few out of cheap.
Build relationships as well as CBGs....