I don't see Tropical Beach as a MUST HAVE to win matches and tournaments.. it just makes things ridiculously easy for you, and sometimes your opponent.
I have the Blastoise/Keldeo deck.. and that was just because half of the deck luckily fell into my hands. So it was pretty cheap for me,
All you would have to do is buy the Blast Kyurem theme deck from stores.. then go individually buy a few blastoise and keldeo. along with a handful of some important trainers and items.. ultimately resulting in a deck less than $100, which is good I might add.
I feel like Darkrai deck would be easy as hell to make. get 4 lasers for like $5 on ebay, buy 3 Darkrai, some Sableye, and a tech attacker, and have at it. [items and supporters like usual as well]
Klink is a cool deck, and because of it.. you can really use a bunch of steel pokemon, which all aren't that expensive. i say buy 2 packs of Dragons, Plasma, Boundaries, and Dark Ex, and see what the cards say to you..
That's always the most fun part