I invested in engl. Drains first start playing Vintage years ago but was disappointed about the averange use of it (I do so with Bazaar and the Shops too later on

). You should realize that the semi-power is pretty expensive but most of the time only narrow in the quantity of decks they use it. In my example I grab my 4 Shops and 4 Bazaars to play Uba-Staxx but then meta accelerated into combo and I was no longer competitive and started another deck leaving me with hundreds of dollars/euros of rarely played cards at home, having a hard time to collect the power 9 itself.
Finally I was shocked by the price the the power 9 so I started with semi power regretting this 'till today. As you'll realize that the deck calls for the cards and not the other way round you'll check the averange vintage deck/meta and the fact that almost every non-workshop deck is blue so I would say that (sounds weired) you'll should start with the most expensive cards first that are also the morst played ones, of course. I would personally rank the cards in strength and quantity of decks they use them.
1. Black Lotus
2. Ancestral Recall (IMO the very best card but in quantity of decks the Lotus is still first)
3. Mox Sapphire (the "on-color" moxen in vintage)
4. Mox Jet (the "on-color" moxen in vintage)
5. Time Walk (best fix-spell in the game)
6. Mox Ruby (the moxen ranked by the averange power of spells in the game in chosen color)
7. Mox Emerald (the moxen ranked by the averange power of spells in the game in chosen color)
8. Mox Pearl (the moxen ranked by the averange power of spells in the game in chosen color)
9. Timetwister (Power 9 sometimes used in Combo)
10. Manadrain (It's blue/counter/mana-advantage)
11. Workshop (Shop calls for expensive artifacs and so a very narrow decktype but still powerfull)
12. Bazaar o. B. (very very narrow but strong use)
The prices are a topic at itself 'cause it varies (here in Germany) very much 'cause of the strength/weakness of the dollar. If you're european you should buy power quickly

with a euro worth about 1,60-1,50 dollar at the moment. So I could not really give you advice but if you need a unlim. Mox Ruby (fine) or any kind/number of semi-power your're welcomed!
