I would suggest Evernote Web Clipper.
Evernote Web Clipper is a simple extension for your web browser that lets you capture full-page articles, images, selected text, important emails, and any web page that inspires you. Save everything to Evernote and keep it forever. (Taken from this)
This extension is available for current modern browser, like Firefox, IE 7+, Safari, Opera, and Google Chrome. First of all, you must have Evernote account in order this extension can be worked. All of your saved clip will be saved into your Evernote account and you can view them forever via web application or desktop application that Evernote provides. Answering what you're looking for:
I can say "yes". Look the extension works below:
Transparent and reliable founders/dev
You can share what you have bookmarked to people who you want to know.
Reasonably price (not above $5/month)
I am so sorry, it's above $5/month for plus plan. You can start this service for free, though. Compare about pricing and feautures here.
Yes, because all your bookmarked clip will be stored in Evernote.
Thumbnail or larger screen shot of bookmarked URL
I suggest see some examples here.
Currently, I am using this extension to clip/bookmark the page what inspires me. I hope this what you're looking for. Feel free to comment.