Greece may not be renowned for snowboarding or for its winter sports in general, but there are some great locations for snowboarding and they won't be jammed. The costs are very low compared to the "big" destinations elsewhere. Lift tickets run 15-20 Euro a day, and snowboard rentals run about the same. Many of the lifts are tow lines, but most resorts have some chair lifts as well. The relatively low prices won't last forever, so enjoy snowboarding in Greece now.
This resort in the Peloponnese provides a snowboard park and a snowtubing park. One of the more popular skiing areas, the prices and waits can be higher here. On New Year's Eve, they throw a party in the parking lot. The "Ski bus" from Athens serves Kalavrita.
This site is mainly in Greek, but some notations are in English. Board Generation operates a bus to Parnassos and Kalavrita on Saturdays in the snow season. Expect to pay 12-15 Euro. Their telephone number in Athens is 210-671-3879; add 011-30 if you're calling from the States.
Sadly, this hasn't been updated in a long time, but it gives a brief look at the start of Snowboarding in Greece.
Get around Europe cheaply if you are 26 or younger by using the Youth Rail Pass. Greek trains are somewhat limited - buses may at times be a better option - but for long-haul trips, thsi is another way to visit Greece on a budget.
This three-country pass is a great way to get around the Balkan region and into Greece. http://www.tkqlhce.com/click-2376066-10419440?url=http%3A%2F%2Fwww.railpass.com%2Fpd%2FRPE%2FEurail_Select_Pass_Saver_3_Countries http://www.dpbolvw.net/ro80zw41w3JMNRQKQQJLKOMMMRR?url=http%3A%2F%2Frailpass.com%2Fpd%2FRPE%2FEurail_Select_Pass_Youth_3_Countries"
Choose from a selection of Rail Passes which will get you to and from Greece and across the rest of Europe, depending on your selection. Read the restrictions carefully; some passes are for consecutive days of travel, others let you take a break in a country on your way, and so on. Remember you still generally need to reserve your seat in advance.