Here is a list of items worth gambling early ladder on Classic
The lvl indicated is to have a 1/2,000 chance of gambling this unique item
(price) is indicated at lowest lvl requirement for that chance ratio, but will go up on further lvlups
Dagger - Gul - lvl 11 to 26+ (1.6k)
Chain Gloves - Chancies - lvl 25+ (6k)
Blade - Spectral Shard - lvl 39+ (12.5k)
Maul - Bonesnap - lvl 37+ (11.7k)
gothic shield - The Ward - lvl 40+ (31.5k)
As you can see, the low gambling prices and access to it very early (1st hour of reset) makes one of the highest profit margin on day 1 of ladder, as Classic prices are way higher than expansion.
Happy early gambling for those looking to make easy profit