buy from swap/shop here for best deals, nicest plants. Peoples trim their tank and rather than throw away cuttings, will offer at a reasonable price.
Great selection, quality plants, good for hobby, good for hobbyist.
This is the best place to get alot of plants. Post a thread offering some money and the plant name you are looking for. The folks here who have some will get in touch with you. You can also respond to one of the for sale threads some of which are insanely cheap. Another option is aquabid.com
If you go that way it will cost you more IMO.