Hi Calvin:
Yes, people use eBay for selling a lot of camera gear. Here are a few of suggestions:
1) Search on "completed listings" on eBay to get an idea of what your gear is worth. Its a good way to do an "apples of apples" comparison. Generally, an item sells for more if worldwide shipping is offered, but there is more risk involved. This is one thing you want to look for in the listings to ensure parity in comparisons.
In addition, figure in eBay fees, PayPal fees, S&H, etc. for you actual net amount.
Be ready for a shock. A12 film backs, excellent to Mint w/matching serial numbers and boxes go for $90-$110!
2) Since you are in the greater Puget Sound area, I would possibly try Craigslist.org for selling the gear. After you look at eBay you get an idea of what the gear may be worth. When selling on Craigslist, you can meet at a Peet's/Starbucks/SBC/Tully's face-to-face. The buyer plays with the gear; you strike a deal; gives you cash [No checks or MOs ever]; you all go home happy.
3) You may also be able to work a deal at Kenmore Camera or Glazers and do a "used for used" trade. This usually only works well if you have a relationship with a shop and are considered a "regular". The camera store in our area has given me some good "used for used" deals. I got my Canon EF 70-200 mm F2.8L IS that way.
4) If you decide to go eBay, you may have a friend who is an "eBay expert"-- have him/her sell the gear for you and work out a dinner or something.
Good luck!
All the best,
Rich
NGOphotographer