Hopefully Crow will see your post and chime in as she knows what she's talking about when it comes to coins. Personally, I would list coins as auctions. Most will get more than one bid. Always start an auction at the lowest price you're willing to accept. A lot of larger sellers will start at 99c, but they know they will get lots of bidders. I would advice against that for yourself.

If you have sold before, but not for awhile, you don't have to start again. If you previously gained, say a 100 item listing limit, you will still have that (up from 10 that you have when you first start). The only difference is, you will be subjected to PayPal's 21 day funds hold. You can get the funds released earlier by giving them a call, giving them a tracking number that shows delivered, and they'll release them while you are on the phone. 

Crow will probably agree, when it comes to coins, do NOT ever send without tracking. If you want to send as large letter, send registered. That includes a tracking number and signature on delivery. As soon as you start sending untracked, you'll start getting item not received disputes against you. You will lose and be forced to refund the scammers buyers.

Even if you have a listing limit of 100, you still only get 40 free listings a month. However, if you are fortunate enough to get the $1 listings of a weekend, then you can list up to your limit, and only pay $1 in FVF's. Every now and then eBay will issue a totally fee free promotion, where you pay no fees if something sells. Keep an eye out for them. I get the $1 promo every weekend, so I only list of a weekend. I couldn't tell you the last time I used any of my 40 freebies!