Should I get an online degree in computer science (University of the People), a traditional degree (Cal State), or focus on my work?

 

You're correct that the largest pay raises you'll see come from changing jobs.  But you can also get to $130k by getting another offer and negotiating a raise to stay, or by getting promoted where you are.  Which brings me to my first question:

How many folks with grey hair are there doing SWE at your current job?  SWE has a deserved bad reputation of hiring kids for high salaries and then replacing them with new kids after the first batch of kids have aged enough to want to be paid significantly more.  If your company is willing to hire SWEs for $100k without a degree, well, that's who you're going to be competing against in five years when you are asking for $130k.  The newbie will be seen as having unlimited upside.  Your upside will be a known quantity.  How you deal with this will be up to you, but be aware that your perceived value needs to be both increasing and significantly higher than your cost.

One of the ways of dealing with aging out is to get into project management.  Talk to your line management and HR and see if those positions require a college degree.  If that's a path you're potentially interested in, see if your employer will cover tuition.  You should be pitching the idea to them on several levels:  they get a more valuable employee, they don't have to replace you, you'll be starting a pipeline of great interns, there may be synergies with the university, etc.  If an online degree is ok with your employer, well.... maybe.  I expect, though, that they'll want to pay for a traditional degree.

Last comment:  you should be networking.  That can mean anything from talking to customers to supporting your local hacker space to attending meetups for the startup community.  If this benefits your employer --- great!  If you're seen as the go-to person for finding new hires then they're going to be very reluctant to let you go.  But some of it can be for your benefit as well.  You'll get a better sense of who else is hiring and what skills (and degrees) they're expecting.  If you've been plugged in for a couple of years and you're seeing a trend that only MS-holders are getting high-paying jobs (say, if the current tech bubble bursts), then you need to prioritize getting your undergrad degree and start planning on the MS.

Good luck!