Jimenez Deal Forces Closer Look at Prospect Value

http://sports.yahoo.com/mlb/news?slu...ospects_073111

Here's the part I found interesting:

“Here’s the thing,” the scout said Friday. “If you have a chance to get a known quantity, someone who has been there and done that, you do it. Do you understand?”

Ubaldo Jimenez is 27 years old. He arrived in 2007 with an odd delivery in which his arms seem to cantilever in the wrong direction. Somehow he coaxed 100-mph fastballs from that funk. Last year, his fastball, splitter, slider and curveball played together with harmonic beauty. Jimenez started 13-1 with a 1.15 ERA – one of the best starts in history and the blossoming of a toolset that reminded scouts why they value projection over production.
I really want to agree with this scout. He is 100% correct. Go with the sure thing ... until you remember that Jimenez was a prospect too, and It seems to me that it would be 10x better to have Jimenez at 20 or 21 years old, than to wait and acquire him at age 27?