First, hello and welcome. We welcome such visitors, from the likes of whom we have bought bottles and cases in the past.
Second is less good. Your bottles are unlikely to be worth a lot. Selling at auction, through one of the big auction houses, is likely to net you about half the retail price. (Auction prices are less than retail which is why wine merchants buy at auction, and there is the seller’s commission and transport costs.) Selling to a wine merchant is likely to net you about the same, half retail. As a guide, vintage port (rather than LBV, Crusted, or other types), of a good name, from a good year, four or so decades old, of good provenance, might be as much as £100 a bottle. If not all these ducks are in a row, it will be less. So this will not pay for a car or a holiday: sorry.
So our usual advice is not to sell.
If you were given these bottles as a christening present, we advise that you hold them. When you are thirty or forty years old it will give you great pleasure to open these bottles with friends bottles you will have owned since you were a toddler. (Recall Alan Clark on Heseltine: ‟he had to buy all his furniture”. Your friends will have had to buy their own wine; yours came to you as a child.) Selling will net you small money; holding and drinking later can give you great pleasure.
If you are the father of the vendor, a teenager with non-vinous uses for money, then you are probably the best purchaser. Buy, and share with your offspring when they are old enough to regret having sold.
But if, despite all this, you still want to sell, then we might be the best purchaser. Please describe what you have, and post a picture of the bottle or of the unopened case. When did you acquire it, and where has it been stored? And where is it now located: which country (UK? USA? Other), and approximately where within that?