You know, your posts remind me of an article that I heard of. If I come across it, I will post more info.
A good friend of mine is a SAHM, she took care of my ds for 4 months while I went back to work. She used to be my boss! She read an article that tallied up what the cost would be to hire someone to do everything that a mom does and be "on-call" 24/7/365. It was some absurd amount of money close to 500,000 dollars!
You have jobs! It sounds like you are really enjoying being a SAHM. You should be proud of yourself for doing what you love, and taking on paying work as you see fit to help fund some fun.
I think all moms go through this thought process. I have done WOHM, WAHM, SAHM and now work part time in a combo of WAHM/SAHM. I have had mixed feelings about each of these situations. I guess we just have to feel out what works best for us.
I think getting your son involved in chores is a great idea. My 2 yr old loves to "help". I am sure this is just a phase, but for now I encourage it.
My sisters two kids, who are in high school, do not know how to do their own laundry yet! I am flabergasted.