Here is the full list of all 40 Pickers achievements.
Buy a Maffler Man
Buy a Motorized Scooter from Hambone Richards
Buy a Movie Projector
Buy a group of items at less than 65% of the asking price
Change a character's mood to green in one transaction
Auction 20 items for a profit
Buy a Vampire Hunting Kit
Buy a Jukebox
Unlock all locations in the game
Reduce your store inventory to one page anytime after the 20th day
Consult the Expert 20 times
Buy and sell 20 items from the Hot Category
Sell 5 items from Lizzie Davis' crawl space
Complete a hidden object scene in under a minute
Complete 5 unique hidden object scenes
Make a profit 5 days in a row
Buy an item at less than 75% of the asking price
Combine two items to create something new
Buy and sell an item from the Hot Category
Restore an item
Restore all items before they are sold
Make a 300% profit in an auction
End a day with two or more characters liking you (in green)
Create 10 new items using the combine tool
Complete each hidden object game without using the scanner
Complete each hidden object game without using any hints
Collect 40 keys to unlock Unlimited Hidden Object Mode
Find all 60 keys
Explore every scene, hidden object game, and close up in the first 6 location
End a day with Patrick Merman in a green mood
Reach the Number 1 Rank!
Maintain the leader position for 7 days
Bring an owner's mood from angry (red) to happy (green) in one day
Buy an Accordion
Combine a Suit of Armor with a Sword
Buy CJ Baxter's safe
Buy a Sun Clock
Buy a Bigfoot Photo
Buy a Snow Globe
Buy a WWII Helmet