I have to agree, the infamous 'wallet' has a really big part to play in coax selection for me. That's after I factor in the length needed, wanted, or "think I might use sometime in the future" thingys. Some days I can order that spool of cable and never hear a peep out's that wallet. Then again, at certain times of the year, it's 'newspaper' soup time and that spool of coax doesn't get ordered. I figure that's about as 'normal' as it gets, except for that 'newspaper' soup thingy, and that's just a matter of taste, sort of.
What's the best length for CB use, or ham, or any other service? Usually, a 500 foot spool lasts me for a very long while. Don't think I've ever bought more than that at one time. Sound like a bit 'much'? Of course it is, but just about as much sense as other 'specific' lengths for some reason other than timing/phasing for a legitimate purpose. Which translates as use what it takes to get from here to there with just a little more because you may wanna move stuff later. The only really important factors in that are impedances. The -system- impedances should all the be the same. That starts at the output of the transmitter, goes to the input of whatever is next in line, then repeat those last 10 words till you get to the antenna. The antenna ought'a have the same input impedance as the rest of the system. If you do that, the length of the feed line, or sections of feed lines, will make absolutely no difference. Make them the required "here to there" lengths. That means the whole @#$ antenna system is 'matched', will work well. Basically has nothing to do with brands or 'types' of coax/feed line. Then the only 'losses' you will see will be resistance related, which actually amounts to very, very little.
None of that says anything about how well the whole mess will radiate. That's a function of the antenna, not the feed line. The feed line's only job is to get the signal from transmitter to the antenna. What the antenna does with it just ain't in the feed line's job description (sort of like the old lady suing the guy's burro who grew the coffee beans because she got burned, you know?).
There you go, the long winded way of saying something that's been common knowledge for a long time... but I'll bet you remember it.
- 'Doc