The short answer to your question is 'No'. Even if you had all the up-to-date (printed) price guides (e.g. Millers) the chances are that you wouldn't be able to find an identical item (in an identical condition) to the one which you want to value. Exactly the same applies to websites giving valuations to antiques. (There are some sites where you pay a fee for an 'expert' to value an item from a photograph but you've no idea whether the 'expert' is genuine or just an enterprising schoolkid).
By far the easiest way to get antiques valued, free of charge, is to take them to any auctioneer. (For larger items, of course, you'll have to take photographs). Auctioneers are normally happy to value items because, naturally, they're hoping that you'll use their services). I've had hundreds of items valued (always free of charge) this way. Many of these valuations have been by small local firms of auctioneers but I've also turned up at Bonham's in London, without an appointment, and had lots of free advice from one of the 'Antiques Road Show' experts.
Chris
(PS: You can try pricing antiques by looking for similar itemson eBay but, if you do so, check that you're looking at genuine bids and not the over-optimistic figure which the vendor has set for a [non-existent] opening bid).