By looking at graded vs ungraded prices you can calculate if the overall cost of grading (shipping x 2 and the cost of the grading itself) would be more or less than the value added by completing the grading process, as well as what grade would be required to potentially turn a profit
Thermopod can help to keep the party going by getting rid of the rowdy partygoers and making mana for more spells
The need for many creatures makes Gaea's Cradle more restrictive than other fast mana, but its still amazing
Altar of Dementia can be combined with the buffed goblins that can be mass-created with Krenko, Ashnods Altar generates two colorless mana for each sacrificed creature, as does Sol Ring
In this case, you can hardly blame the people buying it
Mirror-Style Master also has some unimpressive stats, but the fact it can spit out temporary, token copies of your modified attacking creatures is great especially when those creatures have enter the battlefield abilities