Ore Busters are up around 50k atm, with their Fortune 5. Because of their ability to dramatically increase the diamonds you can get. (someone valued the orebuster at over 1mil worth of extra diamonds, over fortune 3). The Holiday Pick's fortune 4 and slightly useful unbreaking 5 (extra 5-8% durability over unbreaking 3) could be valued the same way. In that it would bring in maybe 600k worth of diamonds over fortune 3. It is also 'soulbound' which means people won't loose them on death, making it more valuable, but also less rare (because ore busters get lost). However, it's also a lot more common than the Ore Buster was due to how many entered circulation. So I can easily see a holiday Pick being 'worth' up to 100k. However, it won't reach that value until supply is limited. Recently they have sold for around 12k, but i'd be putting that value up to 20k easily anytime soon. Depends on how well you promote it.
Holiday Picks are worth about 20k, sometimes creeping up to 25k Ore Busters have fortune 5 and are in limited supply. They are not soulbound. Holiday Picks have less fortune (4) and are in quite a vast suplly still. They are soulbound which means the price will go up slower = comparing it to the ore buster, about 20k