It's easy to cure your fears about those prices for 4X5 color film. Start shooting it in 8X10 instead, and then 4X5 will seem cheap. I don't shoot as much 8x10 as I used to, and admit to working off my reserve of it stockpiled n the freezer, purchased when it cost about one fourth as much as today - in other words, back when 8x10 cost about the same as 4X5 today. But when you're enlarging an 8x10 Ektar original onto a 24X30 or 30X40 inch Fuji Supergloss print, now that is a marriage made in heaven!
I sold off my boxes of 8X10 transparency film after Cibachrome was discontinued. Now I either print directly onto RA4 medium from color neg originals, or else make precision internegatives from older on-hand transparencies. But sheet film is indeed getting expensive, so I ration it, and supplement it with 120 roll film whenever big enlargements are not in mind.
Both C41 and E6 processing are easy to get locally; and in my case, it wouldn't save me any money at all to do it in-house, given the extra fuss involved. I do develop all my own black and white film, since there are so many potential variations of that kind of thing. But C41 and E6 are standardized processes, which monitored big machines can do more reliably. And all my printing, both color and black and white, is done by myself. I'm highly equipped for that.