Welcome to the forum! We all love Casascius coins, so you have come to the right place!
As others have suggested, please upload some pictures of your coins (along with a note with the current date and your forum username) to Imgur and make a post with the links. One of us will then show the images for you.
As for escrow, usually the seller and buyer would choose a mutually agreeable person on the forum to act as escrow in a deal - not a company. There are a number of people on this forum that are trusted to act as that third party - such as Blazed, OgNasty, and minerjones, to name a few. Nearly all deals made on this forum are in bitcoin, and not fiat currency such as US dollars, unless you are able to arrange a face to face meeting with a
trusted forum user from your part of the USA.
If someone sends you a message asking you to meet for a face to face deal, make sure you do some due diligence to ensure they are legit. You have some valuable coins there, and you are new here - be wary of scammers.
Have you ever used a bitcoin wallet before? As this would likely be required for you to sell these (as this is how you will be paid). If you then wanted dollars, you would send those bitcoins to an exchange such as Circle or Coinbase for example, where you can cash out into US $. Bear in mind that registering with these entities requires AML/KYC checks - so you will have to prove your identity and link a bank account/debit card to cash out. It is a lot easier if you had all of this set up already.
May I ask how you obtained these coins? Did you buy them on this forum, direct from Mike Caldwell (Casascius), or did you use somewhere like eBay?
As for the values of these coins, here is a rough estimate.
Your Casascius All Silver 1 BTC coins are not worth 3.5 BTC in current market conditions unfortunately. Ungraded Silvers have been selling for around 2 BTC each lately, maybe a little less depending on the quality. Some high graded ones have even gone for less than that recently. 2 BTC is ~$1,430 as of the time of this post.
Your MS63/65/65 Casascius 2013 0.5 BTC Brass coins are worth around 0.7-0.75 BTC each, maybe a little more depending on a few factors. If those coins were graded by ANACS a good while ago, then they could potentially grade higher if sent back. This would increase the value of them slightly. A rough estimate of value for an ungraded 2013 Brass 0.5 BTC in US $ is around ~$500 - $550 each. Again, we need the pictures to give you a better idea of value, this is just a rough valuation.
All in all, you have around 8.1-8.5 BTC worth of value across your 6 coins - which is roughly $5,750-$6,000, for
all of them. Getting cash is going to be hard, unless you put them on eBay.
If you know how to use a bitcoin wallet, this will be much easier for you. If you don't, selling your coins on this forum will be difficult, unless you find a trustworthy member in your area who will meet you and pay you cash for them.
Hope this post helped!
Looking forward to seeing the pictures
Cheers
