As @tressygirl says, you can tell prospective buyers your reserve price if they ask you.
With regards to using reserves on lisings, to be honest I'd say that it's a bit pointless. The reason I say this is because eBay will still charge you for having used a reserve on the listing, even if the item doesn't even sell. Therefore I would suggest that if you want a certain amount for the item then you either advertise the item as a Buy It Now listing so that potential buyers can see the price that you want for the item. You can also include the Best Offer function if you are willing to accept offers, although eBay have recently put a lot of buyers off of using the Best Offer function by automatically opting sellers in to a requirement which asks buyers to disclose their payment details before the offer has even been sent. You can, however, deactivate this option so that buyers aren't forced into disclosing their payment details before they can even submit their offer for consideration.
The other option would be to list the item as an Auction listing, with a Buy It Now option included as well. That way if somebody sees the listing but doesn't want to have to wait for a week to see if they can submit the highest bid and win the auction they can just use the Buy It Now option to purchase the item outright if they are happy to pay the full amount. However, if somebody were to place a bid in the auction then the Buy It Now option would vanish from the listing and you wouldn't be able to reinstate it.
