Neodymium Magnets

• 40 cents - 1/2" - [1]
• 10 cents - 10x2 N50 - [2]
• 30c 1/2" [3]
• 40 cents 12x3 n52 - [4]
• 20 cents @ 100, 12x3 n52 - [5]
• 17 cents 12x3 from china - [6]
• 17 cents 12x3 @ 1000 from UK - [7]. This appears to be the best option.
• 7 cents 10x2 HK (looks like 1/16" thickness) - [8]. While this looks cheaper, this is not because of the lower strength of 10x2.
• 11 cents 12x2 - [9]
• 18 cents 20x10x2 - [10]

Strength

• 12x3mm appears to be 8 lb - [11]
• 10x3mm is 5.5 lb - [12]
• 20x10x2mm is 4.8 lb - [13]
• 10x2mm n52 is 2.6 lb - [14]
• 12x2mm n52 is 3.8 lb - [15]
• 6x3mm n52 is 2.9 lb - [16]
• 6x6mm n52 is 4.2 lb - [17]

Notes

• 2 mm compared to 3 mm appears to be 1/2 as strong. 2 mm is really 1.6 mm, of 1/16", compared to 1/8", or 3 mm. That makes sense.
• Thus, it's more favorable to go with 3mm thickness.

Tested

• Ebay [18] - 25 for $11 - 48 cents.