Going from least expensive / shortest onsale time item to most expensive / longest onsale time item :

All event items (0 bricks) - Varies

Cone of Beginnings (2 bricks) - Onsale for 1 day

Polytoria Gold Chains (5 bricks) - Onsale for 39 minutes (stocked)
Bandaged (5 bricks) - Onsale for 3 days

Baconator (10 bricks) - Onsale for 2 hours
Teapoor (10 bricks) - Onsale for 3 days

Anniversary Smile (15 bricks) - Onsale for 14 minutes (stocked)
Pirate's Treasure (15 bricks) - Onsale for 2 days

DJ Headset (20 bricks) - Onsale for 1 day

Rockstar (25 bricks) - Onsale for 4 days
Frozen Cyclops (25 bricks) - Onsale for 10 days
Holiday Witch (25 bricks) - Onsale for 12 days (stocked)

Lapis Unga Bunga (40 bricks) - Onsale for 5 hours (stocked)
Jade Unga Bunga (40 bricks) - Onsale for 1 day
Paper Bag: Starlight (40 bricks) - Onsale for 4 days

Midas' Cone (50 bricks) - Onsale for 1 day
Amethyst Scythe (50 bricks) - Onsale for 2 days (stocked)
Pillowphones (50 bricks) - Onsale for 3 days
Jungle Trooper (50 bricks) - Onsale for 4 days
Red Ornamented Ski Mask (50 bricks) - Onsale for 7 days

Television from the Future (70 bricks) - Onsale for 4 days

Silly (75 bricks) - Onsale for 4 days

Exotic Blue Headdress (100 bricks) - Onsale for 5 minutes (stocked)
Violet Bowler Hat (100 bricks) - Onsale for 4 days
Operator: Elf Force (100 bricks) - Onsale for 7 days
Mischievous Demon (100 bricks) - Onsale for 7 days

The Golden Carrot (150 bricks) - Onsale for 2 days
Awesome Face (150 bricks) - Onsale for 7 days

Cursed Fedora (250 bricks) - Onsale for 2 days
Red Glowing Eyes (250 bricks) - Onsale for 3 days
Blue Glowing Eyes (250 bricks) - Onsale for 7 days

Entry Vision (300 bricks) - Onsale for 7 days
Deer Top Hat (300 bricks) - Onsale for 7 days

Timekeeper's Top Hat (500 bricks) - Onsale for 1 day

Golden Teeth Smile (800 bricks) - Onsale for 6 days

Cobra Crown (2.5k bricks) - Onsale for 1 day
Amethyst Cobra Crown (2.5k bricks) - Onsale for 4 days
Diamond Cobra Crown (2.5k bricks) - Onsale for 5 days
Ruby Cobra Crown (2.5k bricks) - Onsale for 7 days

**These are not 100% accurate, some onsale times were rounded up

Nice

me when being awesome costed as much as gold