Hello aengus,
As mentioned above, only you can decide. It's different for everyone.
There's a lot of gloom and doom about eBay at the moment, some of which I share and some of which I dont. I hate some of the recent eBay changes. Most of all I hate the constant dribble of change, it's disruptive to both buyer and seller. But It's not all bad...
While some sellers have found success by moving on from eBay, others have tried the change and have failed. It's different for everyone.
I list a few hundred postcards for eBay auction every week, more than half sell first time through, many with multiple bids. As far as I can see other sites offer MUCH lower selling costs but fail to deliver on the % of items sold, that could of course just be that I've failed on other sites where others have succeeded.
So, if I were starting (or starting again) then
..eBay would be a PART of what I'd do. I'd make sure that it wasn't my only venue. eBay is expensive for sellers and the constant fee and policy changes are a real irritation, the time and the costs of dealing with those changes need to be factored in any decision you make on eBay vs the rest.
..I'd avoid opening an eBay store if my listing volumes were going to be low (stores/shops are now an expensive option here in the uk).
..I'd try auctions. Auctions continue to work well at all levels of volume if you have good quality items. Go gently and work at establishing a good solid reputation. You need high star ratings to ensure good visibility on the site; give honest descriptions, pack well, deliver swiftly and provide good customer care and (via the inevitable ups and downs) you'll get there. With auctions, if things don't work out then you've not taken any great risks. If they do work then you have a platform for growth.
..I'd certainly look at the other sites (take a sample of sellers and look at their sales per week to get an idea of how well it might work) & I would try a few auctions on them.
..Building your own site is very much easier than it used to be and the operating costs are remarkably low. However as with everything else it's all about traffic. If you can work out how to get your buyers to your own site then thats great.
Good luck and, as mentioned in the previous post, please tell us how you get on...
Linda