I agree--$20/mo is not expensive but like @thehodge says... it all adds up. I think that in this space tho, you have a huge market of people who are "pre-business" who just couldn't justify 5-10 $20 services a month when they are pre-profit or only making a few hundred a month off of their products. Basecamp could appeal to some of these folks with a sub $10 offering.
I think 37signals won't do that for the same reason Apple won't make a $399 laptop, they don't want to be in that business. That's not the business they're in, and knowing what business you're in and not in is extremely important. I'm sure there are a dozen Basecamp competitors with $10/mo plans that would probably fit your needs.
Agreed. Someone else here already pointed out "hey, time tracking in basecamp is limited - we use harvest and integrate". OK, so now you've got 2 $20/month services (or whatever harvest costs). Then another $10-$20/month for another service. And another. And another. And that's usually $10-$20/month per user. A small company could easily be paying $500/month for a few services for a handful of users. Are they getting $500 or more of value from it? Possibly, but smaller orgs tend to be more gunshy about spending money, however small, without free tiers. Perhaps those are the companies that you don't really want as customers anyway?
