A $300k home will have property taxes of $3000 > $4500 / yr depending on area within the county. You can get mil levy for specific area from assessor. Factors, are Fire / ems / school and other regional services. Do be specific and also check for utility charges for LID (local improvement districts), The developers often get "credits" for adding services which is passed along to residents and purchasers of lots. (usually water / sewer ... and can be $2000 to $20,000, and added to your monthly bills)
Your power and gas should be ~ $180 - $220 / month for family of 4 and reasonable short showers. (our utilities dropped in half when the kids left for college, and I enforce a strict 5 min shower rule, next time I will install a quarter machine, like campgrounds... on TV too...

) When we host my in-laws for a month our $70/ month electric bill doubles. (we don't have gas in our specific area; nor HS internet, nor dsl, nor cable tv...) Do be careful not to buy a home with ceiling radiant cable heat... there are many built in the 1970's and early 80's... they cost a fortune to heat and are very drafty.
I have a few friends living in CW and working at the airbase (refueling and fighter wing... the air rescue guys got shipped out, and we really miss them for local search and rescue needs). If you have kids in school, I'd try to stay on the west side of Camas, to reduce commute, and to have more consistently good schools. OR schools are not known to be great and funding is poor. There are A LOT of home schoolers in each state, and "Running Start" (college instead of High School) is very popular and a benefit in WA, OR has similar, but not as popular program. Try to find a view home, pay a little extra for less space, as I feel the future sales of cookie cutter (commodity homes) will be tough to sell, as the area is overbuilt to weather a recession, but has not been hit too hard, as it is a desired area. When you go to sell one of those, there are 100's of competitors. If you have something unique, (park, view, older craftsman, acreage, privacy lot) you have a better chance when selling. I'd also try to stay on the small size, as future family size / tax burden... makes it wiser to stay small.
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my assessment in the same county went up 18%, but probably due to my contesting it last year and winning a 1% concession, (my neighbor's went up 6%), my comps were 50% less than assessors. ... They do like to punish you for challenging them, and made the comment..."we'll get you next year", as they have for last 20 yrs, several of which I contested. Last yr it was up 80% and my taxes went up ~ 30% as the overall valuation goes up and the obligations are divided equally, leaving a lessor tax increase than valuation increase. (tho my taxes have averaged a 20% increase for 13 yrs running (that means they double every 3.6 yrs)
The 1% cap will have little bearing on future taxation, as it does not include voter approved bonds, and is an overall county threshold requirement (which they can 'bank'), and can be shifted as per desire / need of assessor.