Hi lulilu,
For regular eBayers:
Can list on Auction format but not inventory format.
For store owners:
I choose to list on inventory listing since this is the cheapest for me to list high-end designer items. The caveat is the product won't show at the top of search result.
If you want to sell faster, then you can choose Auction style listing (as a regular eBayers or as a store owner). You will pay higher listing fee for high-priced items if you choose to do so.
Now, it depends on what is your target price, then your Auction listing fee will be determined.
Hope it helps..