the enclosure for pedals or any other components for pedal making, will only be cheap when one buy in bulk of hundred or thousand
for the convenience of just buying few of those for self pleasure, just spend the money at tymc to save trouble on shipping and other worries.
If really want cheap, try simlim tower for plastic enclosure, sheet metal enclosure. Those, are cheaper compared to the typical die cast enclosure for effect kinda. And wanna cheaper 2pdt footswitch, it can be found there as well.
But then, just have to remember, what you get will be what you pay for, those from sl tower while definitely will work for pedals making and stuff, but the quality can be varied by a lot.
for pedal knobs, dont even have to look to rs, just go sim lim tower, there are plenty. But dont ask whether got for effet pedals one, coz the auntie will either laugh at you or think that its weird question, coz knobs are just knobs, as long its the right size, it will fit the pot we use for pedals/geetar.