i apologize in advance for the long post...
i think you may be underestimating tejada a bit. last year, he had 150 RBI's, while most other shorstops had about 75 or less. that's like having another player on your roster for RBI's. i understand he's unlikely to repeat 150 RBI's, but 120 isn't unreasonable...basically, the position scarcity factor makes him extremely valuable. on the other hand, he has lower SB numbers than pretty much every other SS. but just consider how valuable the power boost is.
to demonstrate tejada's value: let's say i have the sixth pick of the draft, and i'm deciding between tejada and manny ramirez (i feel like manny's a good basic guy to use as an alternate mid-first-round pick). i'm going to give rough stat projections for both - i'll try to be on the conservative side for tejada. i'll just pretty much use manny's '04 stats, since there's no reason to expect a major change (maybe a very slight decline...he is getting older, right?)
okay. now if i drafted manny, i don't want to get screwed at SS, right? so i'm going to draft michael young...3rd round, I'm thinking? maybe 4th? (although, maybe 2nd too, depending how the draft is going)
105-20-90-10-.313 (slight reduction in some stats since i'm expecting a few less at-bats)
now, between manny and young, we have: 215-60-220-12-.309
that means, to match manny and young, the hypothetical me who drafted tejada must find an outfielder who hits 110-30-100-8-.313
let's say we use hideki matsui. i think that's a fair estimate for him, perhaps a little low on the RBIs and a hair high on batting average. matsui, by the way, should also go in the third or fourth round.
what's the point of all this? assuming that the stats projected for tejada are basically a minimum, then you're pretty much guaranteed to do just as well by drafting tejada and a solid OF as you will by drafting a top hitter at a deep position along with a solid SS.
So, to recap: Why Tejada's a good pick:
1. you're guaranteed to do just as well by drafting tejada, even if his power numbers drop significantly from '04
2. if tejada does ends up doing better than the conservative estimates i gave, you'll end up ahead of where you would have been by using the 1st round pick on a top hitter at a deep position
3. don't forget that this all assumes that you manage to get your hands on a top SS. what if you end up drafting manny and getting screwed at SS? it's much less likely you'll get screwed to that extent when trying to draft a late outfielder