Black Lotus Project (BLP) was a Magic: The Gathering card pricing website that collected prices from the Magic Online Trading League's (MOTL) weekly price guide. The price guide was updated once per day, and so the prices were collected once per day. BLP collected data from 2008-10-28 to 2013-10-22 after which point MOTL stopped updating its price guide.
When new sets first went on sale, cards from the new sets would quickly be sold among players and show up on MOTL's price sources. It would sometimes take MOTL weeks to update its card lists with the new sets, which unfortunately led to associating prices from new cards with cards from older sets.
The data here is unchanged from MOTL's lists, which means there are periods where old cards normally worth a few cents have short periods of inaccurate high valuations.
The archive consists of 8 CSV files that were dumped from a MySQL database.
artists_artist.csvcards_card.csvcards_cardset.csvcards_dataload.csvcards_setblock.csvcards_valuepoint.csvpricelists_pricelist.csvpricelists_pricelisttype.csv
id: Primary key
name: Name of the author
website: Known site of the author (sparsely populated by hand)
id: Primary key
card_set_id: Foreign key to cards_cardset.csv
name: Name of the card
color: Color of the card ("Multicolor" if more than one)
rarity: One-character rarity of card {"C": "Common", "L": "Land", "M": "Mythic rare", "R": "Rare", "S": "Special (promotional or other)", "U": "Uncommon"}
artist_id: Foreign key to artists_artist.csv
expansion_code: Primary key; 3-character code for expansion used by Wizards of the Coast (WotC)
name: Name of the card set
set_block_id: Foreign key to cards_setblock.csv
motl_abbreviation: Expansion code used by MOTL, which differs primarily in earlier sets; (Example: "Revised Edition" is identified as "3ED" by WotC but as "RV" by MOTL)
release_date: Date expansion was made available for retail purchase
card_count: Number of cards in the set
id: Primary key
date: Date and time load started
prices_used_count: Number of card prices that matched cards in cards_cards.csv at the time of the load and were used for graphs on blacklotusproject.com.
prices_unused_count: Number of card prices that did not match cards in cards_cards.csv at the time of the load and were not used for graphing
id: Primary key
name: Name taken from WotC's Gatherer for set block
id: Primary key
card_id: Foreign key to cards_cards.csv
dataload_id: Foreign key to cards_dataload.csv
price: Average card price in USD of prices within 1 standard deviation of average
standard_deviation: Standard deviation of price set used to calculate price in USD
average: Mathematical mean of prices in price set in USD
high: Highest price in price set in USD
low: Lowest price in price set in USD
change: Change in price in USD from last valuepoint's price (can be negative)
raw_number: Number of prices in price set
date: Creation date of valuepoint
percent_change: Percent change in price from last valuepoint's price (can be negative)
id: Primary key
created_at: Creation date of pricelist
file: Absolute path to original pricelist from MOTL; Prepend "http://blacklotusproject.com/media/" to access the original file
If you do any clean up of the data, make interesting finds, or do anything cool at all, open an issue on GitHub to share: blacklotusproject/data
All data is available under a standard MIT License, which is included in the archive itself. Refer to it for full details, but the gist is: do with this data what you like but always cite your source.