My state has multiple public universities which regularly appear on top 50 lists and for many in demand fields in the top 5 or 10. The CC systems have agreements with the state public universities guaranteeing admission after 2 years attending CC. There are of course requirements that must be met during the 2 years. They vary from school to school, so you do need to target a specific school while attending CC. These requirements generally involve minimum GPA, credit hours earned and required courses. Since the requirements can vary so greatly between schools many of the CCs have counselors dedicated to working with students to make sure they meet the requirements of the specific 4 year school they would like to attend.

The universities were required to enter these agreements by state law. In an attempt to bring in more out of state tuition dollars some have started to voluntarily enter similar agreements with CC systems in other states.

Do some research and see if there are similar arrangements between CCs and public universities in your state or with out of state universities.

tssva is correct, most states have matriculation agreements between the CC system and state college system. So, at worst, you finish your degree at your home states flagship state university (obviously, those vary, but generally, each state has at least one well respected institution). If you're in VA, you "hit the jackpot" and have many choices (UVA, W&M, VT, plus a half-dozen other solid choices).

Locally (VA), students are guaranteed admission to the state university system if they meet a published GPA threshold. That threshold varies by school. The one big caveat - students are not guaranteed placement within specific programs. So, at GMU, an overall GPA of 2.85 is required to transfer, however that is might not be high enough to guarantee placement in their Computer Science program (which is highly competitive and close to fully enrolled).

I don't know how this applies to transferring to an Ivy (or other top-tier private). For the Ivies, I assume the caliber of student who can gain admission is going to figure out the finances (for better or worse). I also assume (big assumption here) that even a "useless" liberal arts degree from Harvard makes one employable at a reasonable salary (vs the same degree from a 2-tier school).

Edit - one "local" private school (Shepherd U, WV) also has a guaranteed transfer program from the local (Northern VA) CC system. They offer a tuition discount to those transfers. http://www.shepherd.edu/nova-transfer-admissions/

Sure, it's a massive generalization. But, no more so than "college is an over-priced waste of time," which is a claim I see repeated on HN and other tech-centric forums.