First off, welcome! You are obviously a talented artist, and we're interested in your art and your expertise! Thank you for checking in!
The link you provided works great. I don't see a need to upload art from the link here unless you want to add additional information like size, medium, pricing, etc... Of course, art not shown in the link can be posted here.
I don't mean to be snarky, but I think you know that the bottom line is that the art is worth what someone will pay for it. And the only way you can really determine that is to put some pieces out there on the market, and raise or lower your prices on future sales as you go. You can also use the auction format on sites like eBay to allow the market to set the price. If you want people on these forums to make offers on your art, they are going to want to know the size for sure, and other information possibly like; what was this drawn on, thick art board, heavy paper, archival quality paper, etc.... What was it drawn with, pencil, pen, crayon, paints, etc.... Whether it comes with a Certificate of Authenticity? How much do you charge for shipping? Whether you are shipping from the US, Canada, or somewhere else? Does the sale include the right to use the art commercially (in products)?
Keep in mind, people on these forums are primarily collectors of old school rpg paper products, and art
was an important part of this hobby. Any art that does homage to old school art, artists, monsters, characters, places, etc... will be of particular interest. Art that was on D&D rpg products will likely be of more interest that other art. Realistic-looking art is likely going to gain more interest than cartoony/anime art. Fantasy will likely sell better here than space or sci-fi art.
Here's a list of the pieces that interested
me the most:
wrath-and-rage-orc-gods-1
freeport-1
BOFskulldugger
lakepeople
If these were roughly 5x7 pieces(the art, not the paper), I'm guessing you could get around $20.00 a piece for each of these. If they were 8x10, $40.00. If they were 10x13, $75. Or something like that. If they were color, you could roughly double these prices. These guesstimates do not include shipping. I would also guess, if you do a good job promoting yourself, become a reputable seller on eBay, and include a Certificate of Authenticity, you could probably get more than the prices I guessed at. I am one opinion.
Good luck!
Truth is worth finding and life is too short to work for money.