i was in the exact same situation in a few cases, even not too long ago, just on the other side. i was the ceo.
we are in webapp development, so basically everything related to that belongs to the company.
now, one of the guys did a really cool tool in his freetime and showed it to us a couple of weeks later.
my first question to him was: how much do you want for it? even though this really had no connection to any of the things we did at the time, not even the plans we had for the future.
still, we agreed on the price and he got paid out immediately.
exactly one month later a client came with somewhat similar needs for his website, so we sold it without any update.
since the the sales price was quite above the aquisition cost, and we had to do no work on it, the guy got a compensation later to become 50/50 with the company in that subject.
me buying stuff from co-workers happened many times, i think it's great when a company has an offer or an opportunity for you, other than your regular job.
it might not change a thing during workdays, though. :)
anyway, i suggest you go for it, try to get best offer you can get, but if you name the price make sure you don't look like a fool by settling in a fraction of your first offer, so price it right!
the technical cofounder has to have knowledge about server side code, database, etc, so at least one of you is totally in picture of what's going on.
also can cooperate with new employees, subcontractors on a technical level, and certainly can act instantly in a given situation...and probably won't complain about working round the clock :)
with such team, i would feel much safer as an investor too.
Improving devices and technologies are taking certain things out of our hands and heads. More and more by the hour actually...
facebook is there to remind us on birthdays for example. now... it might sound stupid, but i don't care about those reminders and i am not that friend of yours who says happy birthday when seeing the alert. i usually log in at night, so if i forgot someones birthday, i let it slip.
i am pretty sure this sounds more than crazy, but i just ignore the part of technologies where they would change my personality...
i just hope the freed up space by advancing technologies will be put to better use, so instead of keeping your wife's birthday or your 34th anniversary in your mind, you'll invent a more efficient way to burn fuel, or thinking smaller, a better combination of spices for your bbq.
one thing i noticed over the years... when i was "down" or my business wasn't going really well (being a freelancer at some point in time) my actual product wasn't that good.
i was basically not delivering quality, so my customers weren't happy and i had to realize that i should call in someone else to help finish assignments. i had to change my position and my title.
when you work as an employee, you may just be fine for that job, being a freelancer or a company owner, you have to produce exceptional quality, and you may still be in trouble collecting payments in time...
so it is very important to know yourself and your skills before making a decision.
try figure out what you're good at, and until you do, you can still help out here or there for some coins or food.
I was asking HN some time ago if I should wait for Y Combinator, or...
Well, i did not apply anywhere else, and it seems i waited until the very last day. I'm glad I waited, though as 7 days ago my application would contain a totally different app. :)
open http://favris.info in your google chrome browser. on the top right you'll see an F, mouseover it, than click. Hit play, and look in the favicon, use your arrow keys to play! :)