Maybe the other German brands (e.g. Wago, Weidmuller, and I think some ASI sutff) are less expensive.
Weidmuller doesn't do 0.1" (or even 2.54mm!!) at all, much to my chagrin.
Phoenix does have some quite affordable products, too, such as the PST/PT series, the 2.5mm PTSM series, the PTSA, and the PTDA series
Depending on your hole size and "wiggle" of the connector pin you can get a 3 way 2.5mm into 2.54 spacing with little stress. You could possibly push it to 4. 2 way certainly works fine. If you combine this with my earlier suggestion of breaking it into 2 and 3 way blocks, and if these Phoenix connectors are that much cheaper, then maybe that is the way to go.
The way we used to build a prototype was much cheaper. None of this "looked at prices online" junk.
Figure out who is the local sales rep in your area. There will be one, you may have to dig. I kept a file of line cards, which sounds very quaint today.
Call them on the phone, yes the phone. Talk to one of the humans.
Tell them you need samples. The project is under NDA, but if the "can't really say, Q clearences and all, you understand" contract comes through it will be about a million pieces a year, month, whatever. Get the sales person excited. You want to hear them drooling on their phone.
Get the samples, and your golden. If you are good, you can also get a free lunch. Too bad the contract fell through. Sigh.
I build the first 10 production units at a startup this way. We did buy a lot of parts, once things took off. I also build a number of prototypes for another company that never became real products. This is how the game is played, so hate the game, not the player.
So, do you have any suggestions on where we might obtain these little scamps at a price that doesn't make my lower lip quiver and my eyes water?
Depending on the layout of your board (and this is a long shot), if you have created it as a matrix on a 0.1" spacing with lots of holes for protyping. You could use 2 rows of 0.2" spacing connectors one set back behind the other and offset by 0.1" (with 45 degree input angle). I could help you source those!
I spend way too much time researching connectors and terminal blocks.
We use PCB & DIN rail terminal blocks extensively, and if you have competent techs, they work very well.
For prototyping, I prefer screw terminals, because you can stuff multiple wires into one connector. However, for production work, I try to specify spring clamp (much faster assembly time, supposedly more reliable) or IDC (which can be great -- IF you can control the terminating wire. IDC's ONLY work for a narrow range of wire & insulation size).
Phoenix Contact's standard stuff can be pricey, so one option is to check out alternate brands (such as OST, TE, and Molex), although my feeling is that Phoenix's quality is better. Maybe the other German brands (e.g. Wago, Weidmuller, and I think some ASI sutff) are less expensive.
Phoenix does have some quite affordable products, too, such as the PST/PT series, the 2.5mm PTSM series, the PTSA, and the PTDA series.
However, when you need a specific size (such as 2.54mm), that can really limit your options. For example, from some quick Mouser searches, that 2.5mm is much more popular than 2.54mm (and cheaper, since you can get a 10-pos PTSA for ~$1).
Finally, use the search, Luke! (Mouser & Digikey both have excellent parametric searching/filtering) I did a quick Digikey search, and found some fixed 2.54mm TB's for <$2.50 (the OST ones).